198 results sorted by ID
Vision Mark-32: ZK-Friendly Hash Function Over Binary Tower Fields
Tomer Ashur, Mohammad Mahzoun, Jim Posen, Danilo Šijačić
Implementation
Zero-knowledge proof systems are widely used in different applications on the Internet. Among zero-knowledge proof systems, SNARKs are a popular choice because of their fast verification time and small proof size. The efficiency of zero-knowledge systems is crucial for usability, resulting in the development of so-called arithmetization-oriented ciphers. In this work, we introduce Vision Mark-32, a modified instance of Vision defined over binary tower fields, with an optimized number of...
A Comparative Examination of Network and Contract-Based Blockchain Storage Solutions for Decentralized Applications
Lipeng He
Applications
Decentralized applications (DApps), which are innovative blockchain-powered software systems designed to serve as the fundamental building blocks for the next generation of Internet services, have witnessed exponential growth in recent years. This paper thoroughly compares and analyzes two blockchain-based decentralized storage networks (DSNs), which are crucial foundations for DApp and blockchain ecosystems. The study examines their respective mechanisms for data persistence, strategies for...
Fuzzy Identity Based Encryption with a flexible threshold value
Sedigheh Khajouei-Nejad, Sam Jabbehdari, Hamid Haj Seyyed Javadi, Seyed Mohammad Hossein Moattar
Public-key cryptography
The issue of data and information security on the internet and social network has become more serious and pervasive in recent years. Cryptography is used to solve security problems. However, message encryption cannot merely meet the intended goals because access control over the encrypted messages is required in some applications. To achieve these requirements, attribute-based encryption (ABE) is used. This type of encryption provides both security and access structure for the network users...
Benchmark Performance of Homomorphic Polynomial Public Key Cryptography for Key Encapsulation and Digital Signature Schemes
Randy Kuang, Maria Perepechaenko, Dafu Lou, Brinda Tank
Public-key cryptography
This paper conducts a comprehensive benchmarking analysis of the performance of two innovative cryptographic schemes: Homomorphic Polynomial Public Key (HPPK)-Key Encapsulation Mechanism (KEM) and Digital Signature (DS), recently proposed by Kuang et al. These schemes represent a departure from traditional cryptographic paradigms, with HPPK leveraging the security of homomorphic symmetric encryption across two hidden rings without reliance on NP-hard problems. HPPK can be viewed as a...
SoK: Post-Quantum TLS Handshake
Nouri Alnahawi, Johannes Müller, Jan Oupický, Alexander Wiesmaier
Cryptographic protocols
Transport Layer Security (TLS) is the backbone security protocol of the Internet. As this fundamental protocol is at risk from future quantum attackers, many proposals have been made to protect TLS against this threat by implementing post-quantum cryptography (PQC). The widespread interest in post-quantum TLS has given rise to a large number of solutions over the last decade. These proposals differ in many aspects, including the security properties they seek to protect, the efficiency and...
When NTT Meets SIS: Efficient Side-channel Attacks on Dilithium and Kyber
Zehua Qiao, Yuejun Liu, Yongbin Zhou, Mingyao Shao, Shuo Sun
Attacks and cryptanalysis
In 2022, NIST selected Kyber and Dilithium as post-quantum cryptographic standard algorithms. The Number Theoretic Transformation (NTT) algorithm, which facilitates polynomial multiplication, has become a primary target for side-channel attacks. Among these, Correlation Power Analysis (CPA) attacks against NTT have received much attention, which aims to recover all the coefficients of the private key in NTT domain. The necessity to recover all these coefficients not only limits efficiency...
Cache Side-Channel Attacks Through Electromagnetic Emanations of DRAM Accesses
Julien Maillard, Thomas Hiscock, Maxime Lecomte, Christophe Clavier
Attacks and cryptanalysis
Remote side-channel attacks on processors exploit hardware and micro-architectural effects observable from software measurements. So far, the analysis of micro-architectural leakages over physical side-channels (power consumption, electromagnetic field) received little treatment. In this paper, we argue that those attacks are a serious threat, especially against systems such as smartphones and Internet-of-Things (IoT) devices which are physically exposed to the end-user. Namely, we show that...
RSA Blind Signatures with Public Metadata
Ghous Amjad, Kevin Yeo, Moti Yung
Cryptographic protocols
Anonymous tokens are digital signature schemes that enable an issuer to provider users with signatures without learning the input message or the resulting signature received by the user. These primitives allow applications to propagate trust while simultaneously protecting the identity of the user. Anonymous tokens have become a core component for improving the privacy of several real-world applications including ad measurements, authorization protocols, spam detection and VPNs.
In...
An Anonymous Authenticated Key Agreement Protocol Secure in Partially Trusted Registration Server Scenario for Multi-Server Architectures
Inam ul Haq, Jian Wang, Youwen Zhu, Sheharyar Nasir
Cryptographic protocols
The accelerated advances in information communication technologies have made it possible for enterprises to deploy large scale applications in a multi-server architecture (also known as cloud computing environment). In this architecture, a mobile user can remotely obtain desired services over the Internet from multiple servers by initially executing a single registration on a trusted registration server (RS). Due to the hazardous nature of the Internet, to protect user privacy and online...
Faster cellular automata cryptosystems with neighbor sequences
Kittiphop Phalakarn, Athasit Surarerks
The encryption processes and cryptosystems are very important. We use them to protect our private information over the Internet. Cellular automata are ones of the computational models that can also be used in cryptosystems. The advantage of the cellular automata is their abilities to work in parallel, and thus can reduce the encryption time. Some applications require the encryption time to be small, so this paper aims to reduce the encryption time of the cellular automata cryptosystems. We...
Quantum Secure Threshold Private Set Intersection Protocol for IoT-Enabled Privacy Preserving Ride-Sharing Application
Tapaswini Mohanty, Vikas Srivastava, Sumit Kumar Debnath, Ashok Kumar Das, Biplab Sikdar
Cryptographic protocols
The Internet of Things (IoT)-enabled ride sharing
is one of the most transforming and innovative technologies
in the transportation industry. It has myriads of advantages,
but with increasing demands there are security concerns as
well. Traditionally, cryptographic methods are used to address
the security and privacy concerns in a ride sharing system.
Unfortunately, due to the emergence of quantum algorithms,
these cryptographic protocols may not remain secure. Hence,
there is a...
A Multivariate Based Provably Secure Certificateless Signature Scheme with Applications to the Internet of Medical Things
Vikas Srivastava, Sumit Kumar Debnath
Cryptographic protocols
Over the last few years, Internet of Medical Things (IoMT) has completely transformed the healthcare industry. It is bringing out the most notable, and unprecedented impacts on human health, and has totally changed the way we look at the healthcare industry. The healthcare sector all around the globe are leapfrogging, and adopting the technology, helping in transforming drastically in a very short span of time. However, as more and more number of medical devices are being connected to IoMT,...
Lightweight Authentication of Web Data via Garble-Then-Prove
Xiang Xie, Kang Yang, Xiao Wang, Yu Yu
Cryptographic protocols
Transport Layer Security (TLS) establishes an authenticated and confidential channel to deliver data for almost all Internet applications. A recent work (Zhang et al., CCS'20) proposed a protocol to prove the TLS payload to a third party, without any modification of TLS servers, while ensuring the privacy and originality of the data in the presence of malicious adversaries. However, it required maliciously secure Two-Party Computation (2PC) for generic circuits, leading to significant...
Video-Based Cryptanalysis: Extracting Cryptographic Keys from Video Footage of a Device’s Power LED
Ben Nassi, Etay Iluz, Or Cohen, Ofek Vayner, Dudi Nassi, Boris Zadov, Yuval Elovici
Attacks and cryptanalysis
In this paper, we present video-based cryptanalysis,
a new method used to recover secret keys from a device by
analyzing video footage of a device’s power LED. We show that
cryptographic computations performed by the CPU change the
power consumption of the device which affects the brightness of
the device’s power LED. Based on this observation, we show how
attackers can exploit commercial video cameras (e.g., an iPhone
13’s camera or Internet-connected security camera) to...
When Messages are Keys: Is HMAC a dual-PRF?
Matilda Backendal, Mihir Bellare, Felix Günther, Matteo Scarlata
Secret-key cryptography
In Internet security protocols including TLS 1.3, KEMTLS, MLS and Noise, HMAC is being assumed to be a dual-PRF, meaning a PRF not only when keyed conventionally (through its first input), but also when "swapped" and keyed (unconventionally) through its second (message) input. We give the first in-depth analysis of the dual-PRF assumption on HMAC.
For the swap case, we note that security does not hold in general, but completely characterize when it does; we show that HMAC is swap-PRF...
A Fast RLWE-Based IPFE Library and its Application to Privacy-Preserving Biometric Authentication
Supriya Adhikary, Angshuman Karmakar
Public-key cryptography
With the increased use of data and communication through the internet and the abundant misuse of personal data by many organizations, people are more sensitive about their privacy. Privacy-preserving computation is becoming increasingly important in this era. Functional encryption allows a user to evaluate a function on encrypted data without revealing sensitive information. Most implementations of functional encryption schemes are too time-consuming for practical use. Mera et al. first...
A note on ``a lightweight mutual authentication and key agreement protocol for remote surgery application in Tactile Internet environment''
Zhengjun Cao, Lihua Liu
Attacks and cryptanalysis
We show that the key agreement scheme [Comput. Commun., 2021(170): 1--18] is insecure against impersonation attacks, because there is a trivial equality which results in the loss of data confidentiality.
GeT a CAKE: Generic Transformations from Key Encaspulation Mechanisms to Password Authenticated Key Exchanges
Hugo Beguinet, Céline Chevalier, David Pointcheval, Thomas Ricosset, Mélissa Rossi
Public-key cryptography
Password Authenticated Key Exchange (PAKE) have become a key building block in many security products as they provide interesting efficiency/security trade-offs. Indeed, a PAKE allows to dispense with the heavy public key infrastructures and its efficiency and portability make it well suited for applications such as Internet of Things or e-passports.
With the emerging quantum threat and the effervescent development of post-quantum public key algorithms in the last five years, one would...
Unlocking doors from half a continent away: A relay attack against HID Seos
Sam Haskins, Trevor Stevado
Attacks and cryptanalysis
HID Global is a major vendor of physical access control systems. In 2012, it introduced Seos, its newest and most secure contactless RFID credential technology, successfully remediating known flaws in predecessors iCLASS and Prox. Seos has been widely deployed to secure sensitive assets and facilities. To date, no published research has demonstrated a security flaw in Seos. We present a relay attack developed with inexpensive COTS hardware, including the Proxmark 3 RDV4. Our attack is...
High Throughput Lattice-based Signatures on GPUs: Comparing Falcon and Mitaka
Wai-Kong Lee, Raymond K. Zhao, Ron Steinfeld, Amin Sakzad, Seong Oun Hwang
Implementation
The US National Institute of Standards and Technology initiated a standardization process for post-quantum cryptography in 2017, with the aim of selecting key encapsulation mechanisms and signature schemes that can withstand the threat from emerging quantum computers. In 2022, Falcon was selected as one of the standard signature schemes, eventually attracting effort to optimize the implementation of Falcon on various hardware architectures for practical applications. Recently, Mitaka was...
Security Analysis of Signature Schemes with Key Blinding
Edward Eaton, Tancrède Lepoint, Christopher A. Wood
Cryptographic protocols
Digital signatures are fundamental components of public key cryptography. They allow a signer to generate verifiable and unforgeable proofs---signatures---over arbitrary messages with a private key, and allow recipients to verify the proofs against the corresponding and expected public key. These properties are used in practice for a variety of use cases, ranging from identity or data authenticity to non-repudiation. Unsurprisingly, signature schemes are widely used in security protocols...
Authenticated Encryption for Very Short Inputs
Alexandre Adomnicai, Kazuhiko Minematsu, Junji Shikata
Secret-key cryptography
We study authenticated encryption (AE) modes dedicated to very short messages, which are crucial for Internet-of-things applications. Since the existing general-purpose AE modes need at least three block cipher calls for non-empty messages, we explore the design space for AE modes that use at most two calls. We proposed a family of AE modes, dubbed Manx, that work when the total input length is less than $2n$ bits, using an $n$-bit block cipher. Notably, the second construction of Manx can...
LATKE: A Framework for Constructing Identity-Binding PAKEs
Jonathan Katz, Michael Rosenberg
Cryptographic protocols
Motivated by applications to the internet of things (IoT), Cremers, Naor, Paz, and Ronen (Crypto '22) recently considered a setting in which multiple parties share a common password and want to be able to securely authenticate to each other. They observed that using standard password-authenticated key exchange (PAKE) protocols in this setting allows for catastrophic impersonation attacks whereby compromise of a single party allows an attacker to impersonate any party to any other. To address...
Classical and Quantum Security of Elliptic Curve VRF, via Relative Indifferentiability
Chris Peikert, Jiayu Xu
Public-key cryptography
Verifiable random functions (VRFs) are essentially pseudorandom
functions for which selected outputs can be proved correct and unique,
without compromising the security of other outputs. VRFs have numerous
applications across cryptography, and in particular they have recently
been used to implement committee selection in the Algorand protocol.
Elliptic Curve VRF (ECVRF) is an elegant construction,
originally due to Papadopoulos et al., that is now under consideration
by the Internet...
Password-Authenticated TLS via OPAQUE and Post-Handshake Authentication
Julia Hesse, Stanislaw Jarecki, Hugo Krawczyk, Christopher Wood
Cryptographic protocols
OPAQUE is an Asymmetric Password-Authenticated Key Exchange (aPAKE) protocol being standardized by the IETF (Internet Engineering Task Force) as a more secure alternative to the traditional ``password-over-TLS'' mechanism prevalent in current practice. OPAQUE defends against a variety of vulnerabilities of password-over-TLS by dispensing with reliance on PKI and TLS security, and ensuring that the password is never visible to servers or anyone other than the client machine where the password...
Beyond the Blockchain Address: Zero-Knowledge Address Abstraction
Sanghyeon Park, Jeong Hyuk Lee, Seunghwa Lee, Jung Hyun Chun, Hyeonmyeong Cho, MinGi Kim, Hyun Ki Cho, Soo-Mook Moon
Applications
Integrating traditional Internet (web2) identities with blockchain (web3) identities presents considerable obstacles. Conventional solutions typically employ a mapping strategy, linking web2 identities directly to specific blockchain addresses. However, this method can lead to complications such as fragmentation of identifiers across disparate networks.
To address these challenges, we propose a novel scheme, Address Abstraction (AA), that circumvents the need for direct mapping. AA scheme...
Verifiable Distributed Aggregation Functions
Hannah Davis, Christopher Patton, Mike Rosulek, Phillipp Schoppmann
Cryptographic protocols
The modern Internet is built on systems that incentivize collection of information about users. In order to minimize privacy loss, it is desirable to prevent these systems from collecting more information than is required for the application. The promise of multi-party computation is that data can be aggregated without revealing individual measurements to the data collector. This work offers a provable security treatment for "Verifiable Distributed Aggregation Functions (VDAFs)", a class of...
On TLS for the Internet of Things, in a Post Quantum world
Michael Scott
Cryptographic protocols
The TLS (Transport Layer Security) protocol is the most important, most attacked, most analysed and most used cryptographic protocol in the world today. TLS is critical to the integrity of the Internet, and if it were to be broken e-commerce would become impossible, with very serious implications for the global economy. Furthermore TLS is likely to assume even greater significance in the near future with the rapid growth of an Internet of Things (IoT) -- a multiplicity of internet connected...
Individual Cryptography
Stefan Dziembowski, Sebastian Faust, Tomasz Lizurej
Foundations
We initiate a formal study of individual cryptography. Informally speaking, an algorithm $\mathsf{Alg}$ is "individual" if, in every implementation of $\mathsf{Alg}$, there always exists an individual user with full knowledge of the cryptographic data $S$ used by $\mathsf{Alg}$. In particular, it should be infeasible to design implementations of this algorithm that would hide $S$ by distributing it between a group of parties using an MPC protocol or outsourcing it to a trusted execution...
Wi-Fi Security: Do We Still Have to Look Back?
Karim Lounis
Attacks and cryptanalysis
Wi-Fi is a wireless communication technology that
has been around since the late nineties. Nowadays, it is the
most adopted wireless short-range communication technology in
various IoT (Internet of Things) applications and on many wireless
AI (Artificial Intelligent) systems. Although Wi-Fi security
has significantly improved throughout the past years, it is still
having some limitations. Some vulnerabilities still exist allowing
attackers to generate different types of attacks. These...
Glimpse: On-Demand PoW Light Client with Constant-Size Storage for DeFi
Giulia Scaffino, Lukas Aumayr, Zeta Avarikioti, Matteo Maffei
Cryptographic protocols
Cross-chain communication is instrumental in unleashing the full potential of blockchain technologies, as it allows users and developers to exploit the unique design features and the profit opportunities of different existing blockchains. The majority of interoperability solutions are provided by centralized exchanges and bridge protocols based on a trusted majority, both introducing undesirable trust assumptions compared to native blockchain assets. Hence, increasing attention has been...
Area-time Efficient Implementation of NIST Lightweight Hash Functions Targeting IoT Applications
Safiullah Khan, Wai-Kong Lee, Angshuman Karmakar, Jose Maria Bermudo Mera, Abdul Majeed, Seong Oun Hwang
Implementation
To mitigate cybersecurity breaches, secure communication is crucial for the Internet of Things (IoT) environment. Data integrity is one of the most significant characteristics of security, which can be achieved by employing cryptographic hash functions. In view of the demand from IoT applications, the National Institute of Standards and Technology (NIST) initiated a standardization process for lightweight hash functions. This work presents field-programmable gate array (FPGA) implementations...
LightSwap: An Atomic Swap Does Not Require Timeouts At Both Blockchains
Philipp Hoenisch, Subhra Mazumdar, Pedro Moreno-Sanchez, Sushmita Ruj
Cryptographic protocols
Security and privacy issues with centralized exchange services have motivated the design of atomic swap protocols for decentralized trading across currencies. These protocols follow a standard blueprint similar to the 2-phase commit in databases: (i) both users first lock their coins under a certain (cryptographic) condition and a timeout; (ii-a) the coins are swapped if the condition is fulfilled; or (ii-b) coins are released after the timeout. The quest for these protocols is to minimize...
Survey on Fully Homomorphic Encryption, Theory, and Applications
Chiara Marcolla, Victor Sucasas, Marc Manzano, Riccardo Bassoli, Frank H.P. Fitzek, Najwa Aaraj
Foundations
Data privacy concerns are increasing significantly in the context of Internet of Things, cloud services, edge computing, artificial intelligence applications, and other applications enabled by next generation networks. Homomorphic Encryption addresses privacy challenges by enabling multiple operations to be performed on encrypted messages without decryption. This paper comprehensively addresses homomorphic encryption from both theoretical and practical perspectives. The paper delves into the...
Efficient Constant-Time Implementation of SM4 with Intel GFNI instruction set extension and Arm NEON coprocessor
Weiji Guo
Implementation
The efficiency of constant-time SM4 implementation has been lagging behind that of AES for most internet traffic and applicable data encryption scenarios. The best performance before our works was 3.77 cpb for x86 platform (AESNI + AVX2), and 8.62 cpb for Arm platform (NEON). Meanwhile the state of art constant-time AES implementation could reach 0.63 cpb. Dedicated SM4 instruction set extensions like those optionally available in Armv8.2, could achieve comparable cpb to AES. But they are...
Blockchain Applicability for the Internet of Things: Performance and Scalability Challenges and Solutions
Ziaur Rahman, Xun Yi, Sk. Tanzir Mehedi, Rafiqul Islam, Andrei Kelarev
Applications
Blockchain has recently been able to draw wider attention throughout the research community. Since its emergence, the world has seen the mind-blowing expansion of this new technology, which was initially developed as a pawn of digital currency more than a decade back. A self-administering ledger that ensures extensive data immutability over the peer-to-peer network has made it attractive for cybersecurity applications such as a sensor-enabled system called the Internet of things (IoT). Brand...
2022/453
Last updated: 2022-04-16
Dependable Intrusion Detection System for IoT: A Deep Transfer Learning-based Approach
Sk. Tanzir Mehedi, Adnan Anwar, Ziaur Rahman, Kawsar Ahmed, Rafiqul Islam
Applications
Security concerns for IoT applications have been alarming because of their widespread use in different enterprise systems. The potential threats to these applications are constantly emerging and changing, and therefore, sophisticated and dependable defense solutions are necessary against such threats. With the rapid development of IoT networks and evolving threat types, the traditional machine learning-based IDS must update to cope with the security requirements of the current sustainable...
McFly: Verifiable Encryption to the Future Made Practical
Nico Döttling, Lucjan Hanzlik, Bernardo Magri, Stella Wohnig
Cryptographic protocols
Blockchain protocols have revolutionized the way individuals and devices can interact and transact over the internet. More recently, a trend has emerged to harness blockchain technology as a catalyst to enable advanced security features in distributed applications, in particular fairness. However, the tools employed to achieve these security features are either resource wasteful (e.g., time-lock primitives) or only efficient in theory (e.g., witness encryption). We present McFly, a protocol...
Enhancing AES Using Chaos and Logistic Map-Based Key Generation Technique for Securing IoT-Based Smart Home
Ziaur Rahman, Xun Yi, Mustain Billah, Mousumi Sumi, Adnan Anwar
Cryptographic protocols
The Internet of Things (IoT) has brought new ways for humans and machines to communicate with each other over the internet. Though sensor-driven devices have largely eased our everyday lives, most IoT infrastructures have been suffering from security challenges. Since the emergence of IoT, lightweight block ciphers have been a better option for intelligent and sensor-based applications. When public-key infrastructure dominates worldwide, the symmetric key encipherment such as Advanced...
Auditable, Available and Resilient Private Computation on the Blockchain via MPC
Christopher Cordi, Michael P. Frank, Kasimir Gabert, Carollan Helinski, Ryan C. Kao, Vladimir Kolesnikov, Abrahim Ladha, Nicholas Pattengale
Cryptographic protocols
Simple but mission-critical internet-based applications that require extremely high reliability, availability, and verifiability (e.g., auditability) could benefit from running on robust public programmable blockchain platforms such as Ethereum. Unfortunately, program code running on such blockchains is normally publicly viewable, rendering these platforms unsuitable for applications requiring strict privacy of application code, data, and results.
In this work, we investigate using MPC...
A Systematic Literature Review on Blockchain Enabled Federated Learning Framework for Internet of Vehicles
MUSTAIN BILLAH, SK. TANZIR MEHEDI, ADNAN ANWAR, ZIAUR RAHMAN, RAFIQUL ISLAM
Applications
While the convergence of Artificial Intelligence (AI) techniques with improved information technology systems ensured enormous benefits to the Internet of Vehicles (IoVs) systems, it also introduced an increased amount of security and privacy threats. To ensure the security of IoVs data, privacy preservation methodologies have gained significant attention in the literature. However, these strategies also need specific adjustments and modifications to cope with the advances in IoVs design....
Thora: Atomic and Privacy-Preserving Multi-Channel Updates
Lukas Aumayr, Kasra Abbaszadeh, Matteo Maffei
Cryptographic protocols
Most blockchain-based cryptocurrencies suffer from a heavily limited transaction throughput, which is a barrier to their growing adoption. Payment channel networks (PCNs) are one of the promising solutions to this problem. PCNs reduce the on-chain load of transactions and increase the throughput by processing many payments off-chain. In fact, any two users connected via a path of payment channels (i.e., joint addresses between the two channel end-points) can perform payments, and the...
SoK: Oblivious Pseudorandom Functions
Sílvia Casacuberta, Julia Hesse, Anja Lehmann
Secret-key cryptography
In recent years, oblivious pseudorandom functions (OPRFs) have become a ubiquitous primitive used in cryptographic protocols and privacy-preserving technologies. The growing interest in OPRFs, both theoretical and applied, has produced a vast number of different constructions and functionality variations. In this paper, we provide a systematic overview of how to build and use OPRFs. We first categorize existing OPRFs into essentially four families based on their underlying PRF...
Comment on ``SRAM-PUF Based Entities Authentication Scheme for Resource-constrained IoT Devices''
Michael Amar, Amit Kama, Kang Wang, Yossi Oren
Implementation
The cloud-based Internet of Things (IoT) creates opportunities for more direct integration of the physical world and computer-based systems, allowing advanced applications based on sensing, analyzing and controlling the physical world.
IoT deployments, however, are at a particular risk of counterfeiting, through which an adversary can corrupt the entire ecosystem. Therefore, entity authentication of edge devices is considered an essential part of the security of IoT systems.
A recent paper...
Light the Signal: Optimization of Signal Leakage Attacks against LWE-Based Key Exchange
Yue Qin, Ruoyu Ding, Chi Cheng, Nina Bindel, Yanbin Pan, Jintai Ding
Public-key cryptography
Key exchange protocols from the learning with errors (LWE) problem share many similarities with the Diffie–Hellman–Merkle (DHM) protocol, which plays a central role in securing our Internet. Therefore, there has been a long time effort in designing authenticated key exchange directly from LWE to mirror the advantages of DHM-based protocols. In this paper, we revisit signal leakage attacks and show that the severity of these attacks against LWE-based (authenticated) key exchange is still...
Hardware Implementation of SpoC-128
Ambati Sathvik, Tirunagari Rahul, Anubhab Baksi, Vikramkumar Pudi
Secret-key cryptography
In this work, we present a hardware implementation of the lightweight Authenticated Encryption with Associated Data (AEAD) SpoC-128. Designed by AlTawy, Gong, He, Jha, Mandal, Nandi and Rohit; SpoC-128 was submitted to the Lightweight Cryptography (LWC) competition being organised by the National Institute of Standards and Technology (NIST) of the United States Department of Commerce. Our implementation follows the Application Programming Interface (API) specified by the cryptographic...
The Internet Computer for Geeks
The DFINITY Team
Cryptographic protocols
Smart contracts are a new form of software that will revolutionize how software
is written, IT systems are maintained,
and applications and whole businesses
are built.
Smart contracts are composable and autonomous pieces of software
that run on decentralized blockchains, which makes them tamperproof and
unstoppable.
In this paper, we describe the Internet Computer (IC), which is a
radical new design of blockchain that
unleashes the full potential of smart contracts,
overcoming the...
Reinforcing Lightweight Authenticated Encryption Schemes against Statistical Ineffective Fault Attack
AMBILI K N, JIMMY JOSE
Implementation
The increasing use of resource limited devices with less memory, less computing resource and less power supply, motivates
the adoption of lightweight cryptography to provide security solution. ASCON is a finalist and GIMLI is a round 2 candidate of NIST lightweight cryptography competition. ASCON is
a sponge function based authenticated encryption (AE) scheme
suitable for high performance applications. It is suitable for use
in environments like Internet of Things (IoT) where large number
of...
Divide and Funnel: a Scaling Technique for Mix-Networks
Debajyoti Das, Sebastian Meiser, Esfandiar Mohammadi, Aniket Kate
Applications
While many anonymous communication (AC) protocols have been proposed to provide anonymity over the internet, scaling to a large number of users while remaining provably secure is challenging. We tackle this challenge by proposing a new scaling technique to improve the scalability/anonymity of AC protocols that distributes the computational load over many nodes without completely disconnecting the paths different messages take through the network. We demonstrate that our scaling technique is...
Secure Publish-Process-Subscribe System for Dispersed Computing
Weizhao Jin, Bhaskar Krishnamachari, Muhammad Naveed, Srivatsan Ravi, Eduard Sanou, Kwame-Lante Wright
Applications
Publish-subscribe protocols enable real-time multi-point-to-multi-point communications for many dispersed computing systems like Internet of Things (IoT) applications. Recent interest has focused on adding processing to such publish-subscribe protocols to enable computation over real-time streams such that the protocols can provide functionalities such as sensor fusion, compression, and other statistical analysis on raw sensor data. However, unlike pure publish-subscribe protocols, which can...
Blockchain for IoT: A Critical Analysis Concerning Performance and Scalability
Ziaur Rahman, Xun Yi, Ibrahim Khalil, Andrei Kelarev
Applications
The world has been experiencing a mind-blowing expansion of blockchain technology since it was first introduced as an emerging means of cryptocurrency called bitcoin. Currently, it has been regarded as a pervasive frame of reference across almost all research domains, ranging from virtual cash to agriculture or even supply-chain to the Internet of Things. The ability to have a self-administering register with legitimate immutability makes blockchain appealing for the Internet of Things...
SoK: Tokenization on Blockchain
Gang Wang, Mark Nixon
Applications
Blockchain, a potentially disruptive technology, advances many different applications, e.g., crypto-currencies, supply chains, and the Internet of Things. Under the hood of blockchain, it is required to handle different kinds of digital assets and data. The next-generation blockchain ecosystem is expected to consist of numerous applications, and each application may have a distinct representation of digital assets. However, digital assets cannot be directly recorded on the blockchain, and a...
InterTrust: Towards an Efficient Blockchain Interoperability Architecture with Trusted Services
Gang Wang, Mark Nixon
Applications
Blockchain as a potentially disruptive technology can advance many different fields, e.g., cryptocurrencies, supply chains, and the industrial Internet of Things. The next-generation blockchain ecosystem is expected to consist of various homogeneous and heterogeneous distributed ledgers. These ledger systems will inevitably require a certain level of proper cooperation of multiple blockchains to enrich advanced functionalities and enhance interoperable capabilities for future applications....
SoK: Password-Authenticated Key Exchange -- Theory, Practice, Standardization and Real-World Lessons
Feng Hao, Paul C. van Oorschot
Cryptographic protocols
Password-authenticated key exchange (PAKE) is a major area of cryptographic protocol research and practice. Many PAKE proposals have emerged in the 30 years following the original 1992 Encrypted Key Exchange (EKE), some accompanied by new theoretical models to support rigorous analysis. To reduce confusion and encourage practical development, major standards bodies including IEEE, ISO/IEC and the IETF have worked towards standardizing PAKE schemes, with mixed results. Challenges have...
DPCrypto: Acceleration of Post-quantum Cryptographic Algorithms using Dot-Product Instruction on GPUs
Wai-Kong Lee, Hwajeong Seo, Seong Oun Hwang, Angshuman Karmakar, Jose Maria Bermudo Mera, Ramachandra Achar
Implementation
Dot-product is a widely used operation in many machine learning and scientific computing algorithms. Recently, NVIDIA has introduced dot-product instructions (DP2A and DP4A) in modern GPU architectures, with the aim of accelerating machine learning and scientific computing applications. These dot-product instructions allow the computation of multiply-and-add instructions in a clock cycle, effectively achieving higher throughput compared to conventional 32-bit integer units. In this paper,...
ZPiE: Zero-knowledge Proofs in Embedded systems
Xavier Salleras, Vanesa Daza
Implementation
Zero-Knowledge Proofs (ZKPs) are cryptographic primitives allowing a party to prove to another party that the former knows some information while keeping it secret. Such a premise can lead to the development of numerous privacy-preserving protocols in different scenarios, like proving knowledge of some credentials to a server without leaking the identity of the user. Even when the applications of ZKPs were endless, they were not exploited in the wild for a couple of decades due to the fact...
Using Blockchain to Achieve Decentralized Privacy In IoT Healthcare
Sajad Meisami, Mohammad Beheshti-Atashgah, Mohammad Reza Aref
Cryptographic protocols
With the advent of the Internet of Things (IoT), e-health has become one of the main topics of research. Due to the sensitivity of patient information, patient privacy seems challenging. Nowadays, patient data is usually stored in the cloud in healthcare programs, making it difficult for users to have enough control over their data. The recent increment in announced cases of security and surveillance breaches compromising patients' privacy call into question the conventional model, in which...
Listen to Your Heart: Evaluation of the Cardiologic Ecosystem
Endres Puschner, Christoph Saatjohann, Markus Willing, Christian Dresen, Julia Köbe, Benjamin Rath, Christof Paar, Lars Eckardt, Uwe Haverkamp, Sebastian Schinzel
Applications
Modern implantable cardiologic devices communicate via radio frequency techniques and nearby gateways to a backend server on the internet. Those implanted devices, gateways, and servers form an ecosystem of proprietary hardware and protocols that process sensitive medical data and is often vital for patients’ health.
This paper analyzes the security of this Ecosystem, from technical gateway aspects, via the programmer, to configure the implanted device, up to the processing of personal...
Large-Scale Non-Interactive Threshold Cryptosystems in the YOSO Model
Andreas Erwig, Sebastian Faust, Siavash Riahi
Public-key cryptography
A $(t,n)$-public key threshold cryptosystem allows distributing the execution of a cryptographic task among a set of $n$ parties by splitting the secret key required for the computation into $n$ shares. A subset of at least $t+1$ honest parties is required to execute the task of the cryptosystem correctly, while security is guaranteed as long as at most $t < \frac{n}{2}$ parties are corrupted. Unfortunately, traditional threshold cryptosystems do not scale well, when executed at large-scale...
Onion Routing with Replies
Christiane Kuhn, Dennis Hofheinz, Andy Rupp, Thorsten Strufe
Cryptographic protocols
Onion routing (OR) protocols are a crucial tool for providing anonymous internet communication. An OR protocol enables a user to anonymously send requests to a server. A fundamental problem of OR protocols is how to deal with replies: ideally, we would want the server to be able to send a reply back to the anonymous user without knowing or disclosing the user's identity.
Existing OR protocols do allow for such replies, but do not provably protect the payload (i.e., message) of replies...
SynCirc: Efficient Synthesis of Depth-Optimized Circuits for Secure Computation
Arpita Patra, Thomas Schneider, Ajith Suresh, Hossein Yalame
Implementation
Secure Multi-party Computation (MPC) allows to securely compute on private data. To make MPC practical, logic synthesis can be used to automatically translate a description of the function to be computed securely into optimized and error-free boolean circuits. TinyGMW (Demmler et al., CCS'15) used industry-grade hardware synthesis tools (DC, Yosys) to generate depth-optimized circuits for MPC. To evaluate their optimized circuits, they used the ABY framework (Demmler et al., NDSS'15) for...
Bigdata-facilitated Two-party Authenticated Key Exchange for IoT
Bowen Liu, Qiang Tang, Jianying Zhou
Cryptographic protocols
Authenticated Key Exchange (AKE) protocols, by definition, guarantee both session key secrecy and entity authentication. Informally, session key secrecy means that only the legitimate parties learn the established key and mutual authentication means that one party can assure itself the session key is actually established with the other party. Today, an important application area for AKE is Internet of Things (IoT) systems, where an IoT device runs the protocol to establish a session key with...
Individual Verifiability and Revoting in the Estonian Internet Voting System
Olivier Pereira
Cryptographic protocols
Individual verifiability remains one of the main practical challenges in e-voting systems and, despite the central importance of this property, countries that sought to implement it faced repeated security problems.
In this note, we revisit this property in the context of the IVXV version of the Estonian voting system, which has been in used for the Estonian municipal elections of 2017 and for the Estonian and European parliamentary elections of 2019.
We show that a compromised voter...
Efficient Implementation of Lightweight Hash Functions on GPU and Quantum Computers for IoT Applications
Wai-Kong Lee, Kyungbae Jang, Gyeongju Song, Hyunji Kim, Seong Oun Hwang, Hwajeong Seo
Implementation
Secure communication is an important aspect Internet of Things (IoT) applications in order to avoid cyber-security attacks and privacy issue. One of the key security aspects is data integrity, which can be protected by employing cryptographic
hash functions. Recently, US National Institute of Standards and Technology (NIST) had initialized a competition to standardize lightweight hash functions targeting constrained devices, which can be used in IoT applications. The communication in IoT...
SoK: Understanding BFT Consensus in the Age of Blockchains
Gang Wang
Foundations
Blockchain as an enabler to current Internet infrastructure has provided many unique features and revolutionized current distributed systems into a new era. Its decentralization, immutability, and transparency have attracted many applications to adopt the design philosophy of blockchain and customize various replicated solutions. Under the hood of blockchain, consensus protocols play the most important role to achieve distributed replication systems. The distributed system community has...
Traceable Secret Sharing and Applications
Vipul Goyal, Yifan Song, Akshayaram Srinivasan
Cryptographic protocols
Consider a scenario where Alice stores some secret data $s$ on $n$ servers using a $t$-out-of-$n$ secret sharing scheme. Trudy (the collector) is interested in the secret data of Alice and is willing to pay for it. Trudy publishes an advertisement on the internet which describes an elaborate cryptographic scheme to collect the shares from the $n$ servers. Each server who decides to submit its share is paid a hefty monetary reward and is guaranteed ``immunity" from being caught or prosecuted...
An Intermediate Secret-Guessing Attack on Hash-Based Signatures
Roland Booth, Yanhong Xu, Sabyasachi Karati, Reihaneh Safavi-Naini
Digital signature schemes form the basis of trust in Internet communication. Shor (FOCS 1994) proposed quantum algorithms that can be used by a quantum computer to break the security of today’s widely used digital signature schemes, and this has fuelled intensive research on the design and implementation of post-quantum digital signatures. Hash-based digital signatures base their security on one-way functions that in practice are instantiated by hash functions. Hash-based signatures are...
More efficient post-quantum KEMTLS with pre-distributed public keys
Peter Schwabe, Douglas Stebila, Thom Wiggers
Cryptographic protocols
While server-only authentication with certificates is the most widely used mode of operation for the Transport Layer Security (TLS) protocol on the world wide web, there are many applications where TLS is used in a different way or with different constraints. For example, embedded Internet-of-Things clients may have a server certificate pre-programmed and be highly constrained in terms of communication bandwidth or computation power. As post-quantum algorithms have a wider range of...
SoK: Applying Blockchain Technology in Industrial Internet of Things
Gang Wang
Applications
The proliferation of the Internet of Things (IoT) technology has made ubiquitous computing a reality by broadening Internet connectivity across diverse application domains, thus bridging billions of devices and human beings as well for information collection, data processing, and decision-making. In recent years, IoT technology and its applications in various industrial sectors have grown exponentially. Most existing industrial IoT (IIoT) implementations, however, are still relying on a...
Public Key Encryption with Flexible Pattern Matching
Élie Bouscatié, Guilhem Castagnos, Olivier Sanders
Public-key cryptography
Many interesting applications of pattern matching (e.g. deep-packet inspection or medical data analysis) target very sensitive data. In particular, spotting illegal behaviour in internet traffic conflicts with legitimate privacy requirements, which usually forces users (e.g. children, employees) to blindly trust an entity that fully decrypts their traffic in the name of security.
The compromise between traffic analysis and privacy can be achieved through searchable encryption. However, as...
The Availability-Accountability Dilemma and its Resolution via Accountability Gadgets
Joachim Neu, Ertem Nusret Tas, David Tse
Cryptographic protocols
For applications of Byzantine fault tolerant (BFT) consensus protocols where the participants are economic agents, recent works highlighted the importance of accountability: the ability to identify participants who provably violate the protocol. At the same time, being able to reach consensus under dynamic levels of participation is desirable for censorship resistance. We identify an availability-accountability dilemma: in an environment with dynamic participation, no protocol can...
SoK: Exploring Blockchains Interoperability
Gang Wang
Applications
Distributed ledger technologies like blockchain have gained great attention in both academia and industry. Blockchain as a potentially disruptive technology can advance many different fields, e.g., cryptocurrencies, supply chains, and the industrial Internet of Things. The next-generation blockchain ecosystem is expected to consist of various homogeneous and heterogeneous distributed ledgers. These ledger systems will inevitably require a certain level of proper cooperation of multiple...
Security Analysis of SFrame
Takanori Isobe, Ryoma Ito, Kazuhiko Minematsu
Cryptographic protocols
As people become more and more privacy conscious, the need for end-to-end encryption (E2EE) has become widely recognized. We study herein the security of SFrame, an E2EE mechanism recently proposed to the Internet Engineering Task Force for video/audio group communications over the Internet. Despite being a quite recent project, SFrame is going to be adopted by a number of real-world applications. We inspect the original specification of SFrame and find critical issues that will lead to...
RAGHAV: A new low power S-P network encryption design for resource constrained environment
GAURAV BANSOD
Secret-key cryptography
This paper proposes a new ultra lightweight cipher RAGHAV. RAGHAV is a Substitution-Permutation (SP) network, which operates on 64 bit plaintext and supports a 128/80 bit key scheduling. It needs only 994.25 GEs by using 0.13µm ASIC technology for a 128 bit key scheduling. It also needs less memory i.e. 2204 bytes of FLASH memory , which is less as compared to all existing S-P network lightweight ciphers. This paper presents a complete security analysis of RAGHAV, which includes basic...
MPCCache: Privacy-Preserving Multi-Party Cooperative Cache Sharing at the Edge
Duong Tung Nguyen, Ni Trieu
Edge computing and caching have emerged as key technologies in the future communication network to enhance the user experience, reduce backhaul traffic, and enable various Internet of Things applications. Different from conventional resources like CPU and memory that can be utilized by only one party at a time, a cached data item, which can be considered as a public good, can serve multiple parties simultaneously. Therefore, instead of independent caching, it is beneficial for the parties...
Mesh Messaging in Large-scale Protests: Breaking Bridgefy
Martin R. Albrecht, Jorge Blasco, Rikke Bjerg Jensen, Lenka Mareková
Applications
Mesh messaging applications allow users in relative proximity to communicate without the Internet. The most viable offering in this space, Bridgefy, has recently seen increased uptake in areas experiencing large-scale protests (Hong Kong, India, Iran, US, Zimbabwe, Belarus), suggesting its use in these protests. It is also being promoted as a communication tool for use in such situations by its developers and others. In this work, we report on a security analysis of Bridgefy. Our results...
Anonymous Tokens with Public Metadata and Applications to Private Contact Tracing
Tjerand Silde, Martin Strand
Cryptographic protocols
Anonymous single-use tokens have seen recent applications in private Internet browsing and anonymous statistics collection. We develop new schemes in order to include public metadata such as expiration dates for tokens. This inclusion enables planned mass revocation of tokens without distributing new keys, which for natural instantiations can give 77 % and 90 % amortized traffic savings compared to Privacy Pass (Davidson et al., 2018) and DIT: De-Identified Authenticated Telemetry at Scale...
\(\chi\)perbp: a Cloud-based Lightweight Mutual Authentication Protocol
Morteza Adeli, Nasour Bagheri, Sadegh Sadeghi, Saru Kumari
Cryptographic protocols
Alongside the development of cloud computing and Internet of Things(IoT), cloud-based RFID is receiving more attention nowadays.
Cloud-based RFID system is specifically developed to providing real-time data that can be fed to the cloud for easy access and instant data interpretation.
Security and privacy of constrained devices in these systems is a challenging issue for many applications. To deal with this problem, we propose \(\chi\)perbp, a lightweight authentication protocol based on...
PAS-TA-U: PASsword-based Threshold Authentication with PASsword Update
Rachit Rawat, Mahabir Prasad Jhanwar
Cryptographic protocols
A single-sign-on (SSO) is an authentication system that allows a user to log in with a single identity and password to any of several related, yet independent, server applications. SSO solutions eliminate the need for users to repeatedly prove their identities to different applications and hold different credentials for each application. Token-based authentication is commonly used to enable an SSO experience on the web, and on enterprise networks. A large body of work considers distributed...
Preliminary Hardware Benchmarking of a Group of Round 2 NIST Lightweight AEAD Candidates
Mustafa Khairallah, Thomas Peyrin, Anupam Chattopadhyay
Implementation
In this report, we analyze the hardware implementations of 10 candidates for Round 2 of the NIST lightweight cryptography standardization process. These candidates are Ascon, DryGASCON, Elephant, Gimli, PHOTON-Beetle, Pyjamask,
Romulus, Subterranean, TinyJAMBU and Xoodyak. Specifically, we study the implementations of these algorithms when synthesized using the TSMC 65nm and FDSOI 28nm technologies and Synopsys Design Compiler, targeting various performance trade-offs and different...
ASAP: Algorithm Substitution Attacks on Cryptographic Protocols
Sebastian Berndt, Jan Wichelmann, Claudius Pott, Tim-Henrik Traving, Thomas Eisenbarth
Cryptographic protocols
The security of digital communication relies on few cryptographic protocols that are used to protect internet traffic, from web sessions to instant messaging. These protocols and the cryptographic primitives they rely on have been extensively studied and are considered secure. Yet, sophisticated attackers are often able to bypass rather than break security mechanisms.
Kleptography or algorithm substitution attacks (ASA) describe techniques to place backdoors right into cryptographic...
Specifying cycles of minimal length for commonly used linear layers in block ciphers
Guoqiang Deng, Yongzhuang Wei, Xuefeng Duan, Enes Pasalic, Samir Hodzic
Secret-key cryptography
With the advances of Internet-of-Things (IoT) applications in smart cities and the pervasiveness of network devices with limited resources, lightweight block ciphers have achieved rapid development recently.
Due to their relatively simple key schedule, nonlinear invariant attacks have been successfully applied to several families of lightweight block ciphers.
This attack relies on the existence of a nonlinear invariant $g:\F_2^n \rightarrow \F_2$ for the round function $F_k$ so that $g(x)...
A Secure Software Defined Networking based Framework for IoT Networks
Ambili K N, Jimmy Jose
Implementation
The connectivity is increasing in the world with the increased usage of IoT (Internet of Things) devices. To this end, amount of data that needs to be stored and retrieved securely has increased tremendously, but the IoT devices have a small amount of memory and computation capacity. Consequently, a storage area with a large amount of secured storage space is needed. Software-defined Networking (SDN) is an emerging network technology which implements a new paradigm of insecure applications...
Certificate-Based Parallel Key-Insulated Aggregate Signature Against Fully Chosen-Key Attacks for Industrial Internet of Things
Hu Xiong, Yingzhe Hou, Xin Huang, Saru Kumari
Public-key cryptography
With the emergence of the Industrial Internet of Things (IIoT), numerous operations based on smart devices contribute to producing convenience and comfortable applications for individuals and organizations. Considering the untrusted feature of the communication channels in IIoT, it is essential to ensure the authentication and incontestableness of the messages transmitted in the IIoT. In this paper, we firstly proposed a certificate-based parallel key-insulated aggregate signature...
Election Verifiability Revisited: Automated Security Proofs and Attacks on Helios and Belenios
Sevdenur Baloglu, Sergiu Bursuc, Sjouke Mauw, Jun Pang
Foundations
Election verifiability aims to ensure that the outcome produced by electronic voting systems correctly reflects the intentions of eligible voters, even in the presence of an adversary that may corrupt various parts of the voting infrastructure. Protecting such systems from manipulation is challenging because of their distributed nature involving voters, election authorities, voting servers and voting platforms. An adversary corrupting any of these can make changes that, individually, would...
Deep Learning based analysis of Key Scheduling Algorithm of PRESENT cipher
Manan Pareek, Dr. Girish Mishra, Varun Kohli
Public-key cryptography
The lightweight block cipher PRESENT has become viable for areas like IoT (Internet of Things) and RFID tags, due to its compact design and low power consumption, while providing a sufficient level of security for the aforementioned applications. However, the key scheduling algorithm of a cipher plays a major role in deciding how secure it is. In this paper we test the strength of the key scheduling algorithm (KSA) of the 80-bit key length variant of PRESENT by attempting to retrieve the...
Public-key Authenticated Encryption with Keyword Search: A Generic Construction and Its Quantum-resistant Instantiation
Zi-Yuan Liu, Yi-Fan Tseng, Raylin Tso, Masahiro Mambo, Yu-Chi Chen
Public-key cryptography
The industrial Internet of Things (IIoT) integrates sensors, instruments, equipment, and industrial applications, enabling traditional industries to automate and intelligently process data. To reduce the cost and demand of required service equipment, IIoT relies on cloud computing to further process and store data. Public-key encryption with keyword search (PEKS) plays an important role, due to its search functionality, to ensure the privacy and confidentiality of the outsourced data and the...
Homomorphic string search with constant multiplicative depth
Charlotte Bonte, Ilia Iliashenko
Cryptographic protocols
String search finds occurrences of patterns in a larger text. This general problem occurs in various application scenarios, f.e. Internet search, text processing, DNA analysis, etc. Using somewhat homomorphic encryption with SIMD packing, we provide an efficient string search protocol that allows to perform a private search in outsourced data with minimal preprocessing. At the base of the string search protocol lies a randomized homomorphic equality circuit whose depth is independent of the...
Fast, Small, and Area-Time Efficient Architectures for Key-Exchange on Curve25519
Mojtaba Bisheh Niasar, Rami El Khatib, Reza Azarderakhsh, Mehran Mozaffari-Kermani
Implementation
Abstract--- This paper demonstrates fast and compact implementations of Elliptic Curve Cryptography (ECC) for efficient key agreement over Curve25519. Curve25519 has been recently adopted as a key exchange method for several applications such as connected small devices as well as cloud, and included in the National Institute of Standards and Technology (NIST) recommendations for public key cryptography. This paper presents three different performance level designs including lightweight,...
SAKE+: Strengthened Symmetric-Key Authenticated Key Exchange with Perfect Forward Secrecy for IoT
Seyed Farhad Aghili, Amirhossein Adavoudi Jolfaei, Aysajan Abidin
Cryptographic protocols
Lightweight authenticated key exchange (AKE) protocols based on symmetric-key cryptography are important in securing the Internet of Things (IoT). However, achieving perfect forward secrecy (PFS) is not trivial for AKE based on symmetric-key cryptography, as opposed to AKE based on public-key cryptography. The most recent proposals that provide PFS are SAKE and SAKE-AM. In this paper, we first take a closer look at these protocols and observe that they have some limitations, specially when...
A Level Dependent Authentication for IoT Paradigm
Chintan Patel, Nishant Doshi
Secret-key cryptography
The Internet of Things (IoT) based services are getting a widespread expansion in all
the directions and dimensions of the 21st century. The IoT based deployment involves
an internet-connected sensor, mobiles, laptops, and other networking and computing de-
vices. In most IoT based applications, the sensor collects the data and communicates
it to the end-user via gateway device or fog device over a precarious internet channel.
The attacker can use this open channel to capture the...
Efficient Simultaneous Deployment of Multiple Lightweight Authenticated Ciphers
Behnaz Rezvani, Thomas Conroy, Luke Beckwith, Matthew Bozzay, Trevor Laffoon, David McFeeters, Yijia Shi, Minh Vu, William Diehl
Implementation
Cryptographic protections are ubiquitous in information technology, including the emerging Internet of Things (IoT). As a result of technology migration to a resource-challenged landscape and new threats to cryptographic security, governments and industry are exploring new cryptographic algorithms. While new standards will emerge, however, old standards will not disappear for the time being. It is therefore important to explore platforms where multiple cryptographic deployments can be...
Towards Defeating Mass Surveillance and SARS-CoV-2: The Pronto-C2 Fully Decentralized Automatic Contact Tracing System
Gennaro Avitabile, Vincenzo Botta, Vincenzo Iovino, Ivan Visconti
Cryptographic protocols
Mass surveillance can be more easily achieved leveraging fear and desire of the population to feel protected while affected by devastating events. Indeed, in such scenarios, governments can adopt exceptional measures that limit civil rights, usually receiving large support from citizens.
The COVID-19 pandemic is currently affecting daily life of many citizens in the world. People are forced to stay home for several weeks, unemployment rates quickly increase, uncertainty and sadness...
Self-Secured PUF: Protecting the Loop PUF by Masking
Lars Tebelmann, Jean-Luc Danger, Michael Pehl
Physical Unclonable Functions (PUFs) provide means to generate chip individual keys, especially for low-cost applications such as the Internet of Things (IoT). They are intrinsically robust against reverse engineering, and more cost-effective than non-volatile memory (NVM). For several PUF primitives, countermeasures have been proposed to mitigate side-channel weaknesses. However, most mitigation techniques require substantial design effort and/or complexity overhead, which cannot be...
Phantom of the ADAS: Phantom Attacks on Driver-Assistance Systems
Ben Nassi, Dudi Nassi, Raz Ben-Netanel, Yisroel Mirsky, Oleg Drokin, Yuval Elovici
Applications
The absence of deployed vehicular communication systems, which prevents the advanced driving assistance systems
(ADASs) and autopilots of semi/fully autonomous cars to
validate their virtual perception regarding the physical environment surrounding the car with a third party, has been
exploited in various attacks suggested by researchers. Since
the application of these attacks comes with a cost (exposure
of the attacker’s identity), the delicate exposure vs. application
balance has held, and...
Exploring HTTPS Security Inconsistencies: A Cross-Regional Perspective
Eman Salem Alashwali, Pawel Szalachowski, Andrew Martin
Applications
If two or more identical HTTPS clients, located at different geographic locations (regions), make an HTTPS request to the same domain (e.g. example.com), on the same day, will they receive the same HTTPS security guarantees in response? Our results give evidence that this is not always the case. We conduct scans for the top 250000 most visited domains on the Internet, from clients located at five different regions: Australia, Brazil, India, the UK, and the US. Our scans gather data from both...
On Analysis of Lightweight Stream Ciphers with Keyed Update
Orhun Kara, Muhammed F. Esgin
Secret-key cryptography
As the need for lightweight cryptography has grown even more due to the evolution of the Internet of Things, it has become
a greater challenge for cryptographers to design ultra lightweight stream ciphers in compliance with the rule of thumb that the internal state size should be at least twice as the key size to defend against generic Time-Memory-Data Tradeoff (TMDT) attacks. However, recently in 2015, Armknecht and Mikhalev sparked a new light on designing keystream generators (KSGs),...
A Privacy-Enhancing Framework for Internet of Things Services
Lukas Malina, Gautam Srivastava, Petr Dzurenda, Jan Hajny, Sara Ricci
Applications
The world has seen an influx of connected devices through both smart devices and smart cities, paving the path forward for the Internet of Things (IoT). These emerging intelligent infrastructures and applications based on IoT can be beneficial to users only if essential private and secure features are assured. However, with constrained devices being the norm in IoT, security and privacy are often minimized. In this paper, we first categorize various existing privacy-enhancing technologies...
A Generic View on the Unified Zero-Knowledge Protocol and its Applications
Diana Maimut, George Teseleanu
Cryptographic protocols
We present a generalization of Maurer's unified zero-knowledge (UZK) protocol, namely a unified generic zero-knowledge (UGZK) construction. We prove the security of our UGZK protocol and discuss special cases. Compared to UZK, the new protocol allows to prove knowledge of a vector of secrets instead of only one secret. We also provide the reader with a hash variant of UGZK and the corresponding security analysis. Last but not least, we extend Cogliani \emph{et al.}'s lightweight...
Challenges of Post-Quantum Digital Signing in Real-world Applications: A Survey
Teik Guan Tan, Pawel Szalachowski, Jianying Zhou
Public-key cryptography
Public key cryptography is threatened by the advent of quantum computers. Using Shor's algorithm on a large-enough quantum computer, an attacker can cryptanalyze any RSA/ECC public key, and generate fake digital signatures in seconds. If this vulnerability is left unaddressed, digital communications and electronic transactions can potentially be without the assurance of authenticity and non-repudiation. In this paper, we study the use of digital signatures in 14 real-world applications...
Zero-knowledge proof systems are widely used in different applications on the Internet. Among zero-knowledge proof systems, SNARKs are a popular choice because of their fast verification time and small proof size. The efficiency of zero-knowledge systems is crucial for usability, resulting in the development of so-called arithmetization-oriented ciphers. In this work, we introduce Vision Mark-32, a modified instance of Vision defined over binary tower fields, with an optimized number of...
Decentralized applications (DApps), which are innovative blockchain-powered software systems designed to serve as the fundamental building blocks for the next generation of Internet services, have witnessed exponential growth in recent years. This paper thoroughly compares and analyzes two blockchain-based decentralized storage networks (DSNs), which are crucial foundations for DApp and blockchain ecosystems. The study examines their respective mechanisms for data persistence, strategies for...
The issue of data and information security on the internet and social network has become more serious and pervasive in recent years. Cryptography is used to solve security problems. However, message encryption cannot merely meet the intended goals because access control over the encrypted messages is required in some applications. To achieve these requirements, attribute-based encryption (ABE) is used. This type of encryption provides both security and access structure for the network users...
This paper conducts a comprehensive benchmarking analysis of the performance of two innovative cryptographic schemes: Homomorphic Polynomial Public Key (HPPK)-Key Encapsulation Mechanism (KEM) and Digital Signature (DS), recently proposed by Kuang et al. These schemes represent a departure from traditional cryptographic paradigms, with HPPK leveraging the security of homomorphic symmetric encryption across two hidden rings without reliance on NP-hard problems. HPPK can be viewed as a...
Transport Layer Security (TLS) is the backbone security protocol of the Internet. As this fundamental protocol is at risk from future quantum attackers, many proposals have been made to protect TLS against this threat by implementing post-quantum cryptography (PQC). The widespread interest in post-quantum TLS has given rise to a large number of solutions over the last decade. These proposals differ in many aspects, including the security properties they seek to protect, the efficiency and...
In 2022, NIST selected Kyber and Dilithium as post-quantum cryptographic standard algorithms. The Number Theoretic Transformation (NTT) algorithm, which facilitates polynomial multiplication, has become a primary target for side-channel attacks. Among these, Correlation Power Analysis (CPA) attacks against NTT have received much attention, which aims to recover all the coefficients of the private key in NTT domain. The necessity to recover all these coefficients not only limits efficiency...
Remote side-channel attacks on processors exploit hardware and micro-architectural effects observable from software measurements. So far, the analysis of micro-architectural leakages over physical side-channels (power consumption, electromagnetic field) received little treatment. In this paper, we argue that those attacks are a serious threat, especially against systems such as smartphones and Internet-of-Things (IoT) devices which are physically exposed to the end-user. Namely, we show that...
Anonymous tokens are digital signature schemes that enable an issuer to provider users with signatures without learning the input message or the resulting signature received by the user. These primitives allow applications to propagate trust while simultaneously protecting the identity of the user. Anonymous tokens have become a core component for improving the privacy of several real-world applications including ad measurements, authorization protocols, spam detection and VPNs. In...
The accelerated advances in information communication technologies have made it possible for enterprises to deploy large scale applications in a multi-server architecture (also known as cloud computing environment). In this architecture, a mobile user can remotely obtain desired services over the Internet from multiple servers by initially executing a single registration on a trusted registration server (RS). Due to the hazardous nature of the Internet, to protect user privacy and online...
The encryption processes and cryptosystems are very important. We use them to protect our private information over the Internet. Cellular automata are ones of the computational models that can also be used in cryptosystems. The advantage of the cellular automata is their abilities to work in parallel, and thus can reduce the encryption time. Some applications require the encryption time to be small, so this paper aims to reduce the encryption time of the cellular automata cryptosystems. We...
The Internet of Things (IoT)-enabled ride sharing is one of the most transforming and innovative technologies in the transportation industry. It has myriads of advantages, but with increasing demands there are security concerns as well. Traditionally, cryptographic methods are used to address the security and privacy concerns in a ride sharing system. Unfortunately, due to the emergence of quantum algorithms, these cryptographic protocols may not remain secure. Hence, there is a...
Over the last few years, Internet of Medical Things (IoMT) has completely transformed the healthcare industry. It is bringing out the most notable, and unprecedented impacts on human health, and has totally changed the way we look at the healthcare industry. The healthcare sector all around the globe are leapfrogging, and adopting the technology, helping in transforming drastically in a very short span of time. However, as more and more number of medical devices are being connected to IoMT,...
Transport Layer Security (TLS) establishes an authenticated and confidential channel to deliver data for almost all Internet applications. A recent work (Zhang et al., CCS'20) proposed a protocol to prove the TLS payload to a third party, without any modification of TLS servers, while ensuring the privacy and originality of the data in the presence of malicious adversaries. However, it required maliciously secure Two-Party Computation (2PC) for generic circuits, leading to significant...
In this paper, we present video-based cryptanalysis, a new method used to recover secret keys from a device by analyzing video footage of a device’s power LED. We show that cryptographic computations performed by the CPU change the power consumption of the device which affects the brightness of the device’s power LED. Based on this observation, we show how attackers can exploit commercial video cameras (e.g., an iPhone 13’s camera or Internet-connected security camera) to...
In Internet security protocols including TLS 1.3, KEMTLS, MLS and Noise, HMAC is being assumed to be a dual-PRF, meaning a PRF not only when keyed conventionally (through its first input), but also when "swapped" and keyed (unconventionally) through its second (message) input. We give the first in-depth analysis of the dual-PRF assumption on HMAC. For the swap case, we note that security does not hold in general, but completely characterize when it does; we show that HMAC is swap-PRF...
With the increased use of data and communication through the internet and the abundant misuse of personal data by many organizations, people are more sensitive about their privacy. Privacy-preserving computation is becoming increasingly important in this era. Functional encryption allows a user to evaluate a function on encrypted data without revealing sensitive information. Most implementations of functional encryption schemes are too time-consuming for practical use. Mera et al. first...
We show that the key agreement scheme [Comput. Commun., 2021(170): 1--18] is insecure against impersonation attacks, because there is a trivial equality which results in the loss of data confidentiality.
Password Authenticated Key Exchange (PAKE) have become a key building block in many security products as they provide interesting efficiency/security trade-offs. Indeed, a PAKE allows to dispense with the heavy public key infrastructures and its efficiency and portability make it well suited for applications such as Internet of Things or e-passports. With the emerging quantum threat and the effervescent development of post-quantum public key algorithms in the last five years, one would...
HID Global is a major vendor of physical access control systems. In 2012, it introduced Seos, its newest and most secure contactless RFID credential technology, successfully remediating known flaws in predecessors iCLASS and Prox. Seos has been widely deployed to secure sensitive assets and facilities. To date, no published research has demonstrated a security flaw in Seos. We present a relay attack developed with inexpensive COTS hardware, including the Proxmark 3 RDV4. Our attack is...
The US National Institute of Standards and Technology initiated a standardization process for post-quantum cryptography in 2017, with the aim of selecting key encapsulation mechanisms and signature schemes that can withstand the threat from emerging quantum computers. In 2022, Falcon was selected as one of the standard signature schemes, eventually attracting effort to optimize the implementation of Falcon on various hardware architectures for practical applications. Recently, Mitaka was...
Digital signatures are fundamental components of public key cryptography. They allow a signer to generate verifiable and unforgeable proofs---signatures---over arbitrary messages with a private key, and allow recipients to verify the proofs against the corresponding and expected public key. These properties are used in practice for a variety of use cases, ranging from identity or data authenticity to non-repudiation. Unsurprisingly, signature schemes are widely used in security protocols...
We study authenticated encryption (AE) modes dedicated to very short messages, which are crucial for Internet-of-things applications. Since the existing general-purpose AE modes need at least three block cipher calls for non-empty messages, we explore the design space for AE modes that use at most two calls. We proposed a family of AE modes, dubbed Manx, that work when the total input length is less than $2n$ bits, using an $n$-bit block cipher. Notably, the second construction of Manx can...
Motivated by applications to the internet of things (IoT), Cremers, Naor, Paz, and Ronen (Crypto '22) recently considered a setting in which multiple parties share a common password and want to be able to securely authenticate to each other. They observed that using standard password-authenticated key exchange (PAKE) protocols in this setting allows for catastrophic impersonation attacks whereby compromise of a single party allows an attacker to impersonate any party to any other. To address...
Verifiable random functions (VRFs) are essentially pseudorandom functions for which selected outputs can be proved correct and unique, without compromising the security of other outputs. VRFs have numerous applications across cryptography, and in particular they have recently been used to implement committee selection in the Algorand protocol. Elliptic Curve VRF (ECVRF) is an elegant construction, originally due to Papadopoulos et al., that is now under consideration by the Internet...
OPAQUE is an Asymmetric Password-Authenticated Key Exchange (aPAKE) protocol being standardized by the IETF (Internet Engineering Task Force) as a more secure alternative to the traditional ``password-over-TLS'' mechanism prevalent in current practice. OPAQUE defends against a variety of vulnerabilities of password-over-TLS by dispensing with reliance on PKI and TLS security, and ensuring that the password is never visible to servers or anyone other than the client machine where the password...
Integrating traditional Internet (web2) identities with blockchain (web3) identities presents considerable obstacles. Conventional solutions typically employ a mapping strategy, linking web2 identities directly to specific blockchain addresses. However, this method can lead to complications such as fragmentation of identifiers across disparate networks. To address these challenges, we propose a novel scheme, Address Abstraction (AA), that circumvents the need for direct mapping. AA scheme...
The modern Internet is built on systems that incentivize collection of information about users. In order to minimize privacy loss, it is desirable to prevent these systems from collecting more information than is required for the application. The promise of multi-party computation is that data can be aggregated without revealing individual measurements to the data collector. This work offers a provable security treatment for "Verifiable Distributed Aggregation Functions (VDAFs)", a class of...
The TLS (Transport Layer Security) protocol is the most important, most attacked, most analysed and most used cryptographic protocol in the world today. TLS is critical to the integrity of the Internet, and if it were to be broken e-commerce would become impossible, with very serious implications for the global economy. Furthermore TLS is likely to assume even greater significance in the near future with the rapid growth of an Internet of Things (IoT) -- a multiplicity of internet connected...
We initiate a formal study of individual cryptography. Informally speaking, an algorithm $\mathsf{Alg}$ is "individual" if, in every implementation of $\mathsf{Alg}$, there always exists an individual user with full knowledge of the cryptographic data $S$ used by $\mathsf{Alg}$. In particular, it should be infeasible to design implementations of this algorithm that would hide $S$ by distributing it between a group of parties using an MPC protocol or outsourcing it to a trusted execution...
Wi-Fi is a wireless communication technology that has been around since the late nineties. Nowadays, it is the most adopted wireless short-range communication technology in various IoT (Internet of Things) applications and on many wireless AI (Artificial Intelligent) systems. Although Wi-Fi security has significantly improved throughout the past years, it is still having some limitations. Some vulnerabilities still exist allowing attackers to generate different types of attacks. These...
Cross-chain communication is instrumental in unleashing the full potential of blockchain technologies, as it allows users and developers to exploit the unique design features and the profit opportunities of different existing blockchains. The majority of interoperability solutions are provided by centralized exchanges and bridge protocols based on a trusted majority, both introducing undesirable trust assumptions compared to native blockchain assets. Hence, increasing attention has been...
To mitigate cybersecurity breaches, secure communication is crucial for the Internet of Things (IoT) environment. Data integrity is one of the most significant characteristics of security, which can be achieved by employing cryptographic hash functions. In view of the demand from IoT applications, the National Institute of Standards and Technology (NIST) initiated a standardization process for lightweight hash functions. This work presents field-programmable gate array (FPGA) implementations...
Security and privacy issues with centralized exchange services have motivated the design of atomic swap protocols for decentralized trading across currencies. These protocols follow a standard blueprint similar to the 2-phase commit in databases: (i) both users first lock their coins under a certain (cryptographic) condition and a timeout; (ii-a) the coins are swapped if the condition is fulfilled; or (ii-b) coins are released after the timeout. The quest for these protocols is to minimize...
Data privacy concerns are increasing significantly in the context of Internet of Things, cloud services, edge computing, artificial intelligence applications, and other applications enabled by next generation networks. Homomorphic Encryption addresses privacy challenges by enabling multiple operations to be performed on encrypted messages without decryption. This paper comprehensively addresses homomorphic encryption from both theoretical and practical perspectives. The paper delves into the...
The efficiency of constant-time SM4 implementation has been lagging behind that of AES for most internet traffic and applicable data encryption scenarios. The best performance before our works was 3.77 cpb for x86 platform (AESNI + AVX2), and 8.62 cpb for Arm platform (NEON). Meanwhile the state of art constant-time AES implementation could reach 0.63 cpb. Dedicated SM4 instruction set extensions like those optionally available in Armv8.2, could achieve comparable cpb to AES. But they are...
Blockchain has recently been able to draw wider attention throughout the research community. Since its emergence, the world has seen the mind-blowing expansion of this new technology, which was initially developed as a pawn of digital currency more than a decade back. A self-administering ledger that ensures extensive data immutability over the peer-to-peer network has made it attractive for cybersecurity applications such as a sensor-enabled system called the Internet of things (IoT). Brand...
Security concerns for IoT applications have been alarming because of their widespread use in different enterprise systems. The potential threats to these applications are constantly emerging and changing, and therefore, sophisticated and dependable defense solutions are necessary against such threats. With the rapid development of IoT networks and evolving threat types, the traditional machine learning-based IDS must update to cope with the security requirements of the current sustainable...
Blockchain protocols have revolutionized the way individuals and devices can interact and transact over the internet. More recently, a trend has emerged to harness blockchain technology as a catalyst to enable advanced security features in distributed applications, in particular fairness. However, the tools employed to achieve these security features are either resource wasteful (e.g., time-lock primitives) or only efficient in theory (e.g., witness encryption). We present McFly, a protocol...
The Internet of Things (IoT) has brought new ways for humans and machines to communicate with each other over the internet. Though sensor-driven devices have largely eased our everyday lives, most IoT infrastructures have been suffering from security challenges. Since the emergence of IoT, lightweight block ciphers have been a better option for intelligent and sensor-based applications. When public-key infrastructure dominates worldwide, the symmetric key encipherment such as Advanced...
Simple but mission-critical internet-based applications that require extremely high reliability, availability, and verifiability (e.g., auditability) could benefit from running on robust public programmable blockchain platforms such as Ethereum. Unfortunately, program code running on such blockchains is normally publicly viewable, rendering these platforms unsuitable for applications requiring strict privacy of application code, data, and results. In this work, we investigate using MPC...
While the convergence of Artificial Intelligence (AI) techniques with improved information technology systems ensured enormous benefits to the Internet of Vehicles (IoVs) systems, it also introduced an increased amount of security and privacy threats. To ensure the security of IoVs data, privacy preservation methodologies have gained significant attention in the literature. However, these strategies also need specific adjustments and modifications to cope with the advances in IoVs design....
Most blockchain-based cryptocurrencies suffer from a heavily limited transaction throughput, which is a barrier to their growing adoption. Payment channel networks (PCNs) are one of the promising solutions to this problem. PCNs reduce the on-chain load of transactions and increase the throughput by processing many payments off-chain. In fact, any two users connected via a path of payment channels (i.e., joint addresses between the two channel end-points) can perform payments, and the...
In recent years, oblivious pseudorandom functions (OPRFs) have become a ubiquitous primitive used in cryptographic protocols and privacy-preserving technologies. The growing interest in OPRFs, both theoretical and applied, has produced a vast number of different constructions and functionality variations. In this paper, we provide a systematic overview of how to build and use OPRFs. We first categorize existing OPRFs into essentially four families based on their underlying PRF...
The cloud-based Internet of Things (IoT) creates opportunities for more direct integration of the physical world and computer-based systems, allowing advanced applications based on sensing, analyzing and controlling the physical world. IoT deployments, however, are at a particular risk of counterfeiting, through which an adversary can corrupt the entire ecosystem. Therefore, entity authentication of edge devices is considered an essential part of the security of IoT systems. A recent paper...
Key exchange protocols from the learning with errors (LWE) problem share many similarities with the Diffie–Hellman–Merkle (DHM) protocol, which plays a central role in securing our Internet. Therefore, there has been a long time effort in designing authenticated key exchange directly from LWE to mirror the advantages of DHM-based protocols. In this paper, we revisit signal leakage attacks and show that the severity of these attacks against LWE-based (authenticated) key exchange is still...
In this work, we present a hardware implementation of the lightweight Authenticated Encryption with Associated Data (AEAD) SpoC-128. Designed by AlTawy, Gong, He, Jha, Mandal, Nandi and Rohit; SpoC-128 was submitted to the Lightweight Cryptography (LWC) competition being organised by the National Institute of Standards and Technology (NIST) of the United States Department of Commerce. Our implementation follows the Application Programming Interface (API) specified by the cryptographic...
Smart contracts are a new form of software that will revolutionize how software is written, IT systems are maintained, and applications and whole businesses are built. Smart contracts are composable and autonomous pieces of software that run on decentralized blockchains, which makes them tamperproof and unstoppable. In this paper, we describe the Internet Computer (IC), which is a radical new design of blockchain that unleashes the full potential of smart contracts, overcoming the...
The increasing use of resource limited devices with less memory, less computing resource and less power supply, motivates the adoption of lightweight cryptography to provide security solution. ASCON is a finalist and GIMLI is a round 2 candidate of NIST lightweight cryptography competition. ASCON is a sponge function based authenticated encryption (AE) scheme suitable for high performance applications. It is suitable for use in environments like Internet of Things (IoT) where large number of...
While many anonymous communication (AC) protocols have been proposed to provide anonymity over the internet, scaling to a large number of users while remaining provably secure is challenging. We tackle this challenge by proposing a new scaling technique to improve the scalability/anonymity of AC protocols that distributes the computational load over many nodes without completely disconnecting the paths different messages take through the network. We demonstrate that our scaling technique is...
Publish-subscribe protocols enable real-time multi-point-to-multi-point communications for many dispersed computing systems like Internet of Things (IoT) applications. Recent interest has focused on adding processing to such publish-subscribe protocols to enable computation over real-time streams such that the protocols can provide functionalities such as sensor fusion, compression, and other statistical analysis on raw sensor data. However, unlike pure publish-subscribe protocols, which can...
The world has been experiencing a mind-blowing expansion of blockchain technology since it was first introduced as an emerging means of cryptocurrency called bitcoin. Currently, it has been regarded as a pervasive frame of reference across almost all research domains, ranging from virtual cash to agriculture or even supply-chain to the Internet of Things. The ability to have a self-administering register with legitimate immutability makes blockchain appealing for the Internet of Things...
Blockchain, a potentially disruptive technology, advances many different applications, e.g., crypto-currencies, supply chains, and the Internet of Things. Under the hood of blockchain, it is required to handle different kinds of digital assets and data. The next-generation blockchain ecosystem is expected to consist of numerous applications, and each application may have a distinct representation of digital assets. However, digital assets cannot be directly recorded on the blockchain, and a...
Blockchain as a potentially disruptive technology can advance many different fields, e.g., cryptocurrencies, supply chains, and the industrial Internet of Things. The next-generation blockchain ecosystem is expected to consist of various homogeneous and heterogeneous distributed ledgers. These ledger systems will inevitably require a certain level of proper cooperation of multiple blockchains to enrich advanced functionalities and enhance interoperable capabilities for future applications....
Password-authenticated key exchange (PAKE) is a major area of cryptographic protocol research and practice. Many PAKE proposals have emerged in the 30 years following the original 1992 Encrypted Key Exchange (EKE), some accompanied by new theoretical models to support rigorous analysis. To reduce confusion and encourage practical development, major standards bodies including IEEE, ISO/IEC and the IETF have worked towards standardizing PAKE schemes, with mixed results. Challenges have...
Dot-product is a widely used operation in many machine learning and scientific computing algorithms. Recently, NVIDIA has introduced dot-product instructions (DP2A and DP4A) in modern GPU architectures, with the aim of accelerating machine learning and scientific computing applications. These dot-product instructions allow the computation of multiply-and-add instructions in a clock cycle, effectively achieving higher throughput compared to conventional 32-bit integer units. In this paper,...
Zero-Knowledge Proofs (ZKPs) are cryptographic primitives allowing a party to prove to another party that the former knows some information while keeping it secret. Such a premise can lead to the development of numerous privacy-preserving protocols in different scenarios, like proving knowledge of some credentials to a server without leaking the identity of the user. Even when the applications of ZKPs were endless, they were not exploited in the wild for a couple of decades due to the fact...
With the advent of the Internet of Things (IoT), e-health has become one of the main topics of research. Due to the sensitivity of patient information, patient privacy seems challenging. Nowadays, patient data is usually stored in the cloud in healthcare programs, making it difficult for users to have enough control over their data. The recent increment in announced cases of security and surveillance breaches compromising patients' privacy call into question the conventional model, in which...
Modern implantable cardiologic devices communicate via radio frequency techniques and nearby gateways to a backend server on the internet. Those implanted devices, gateways, and servers form an ecosystem of proprietary hardware and protocols that process sensitive medical data and is often vital for patients’ health. This paper analyzes the security of this Ecosystem, from technical gateway aspects, via the programmer, to configure the implanted device, up to the processing of personal...
A $(t,n)$-public key threshold cryptosystem allows distributing the execution of a cryptographic task among a set of $n$ parties by splitting the secret key required for the computation into $n$ shares. A subset of at least $t+1$ honest parties is required to execute the task of the cryptosystem correctly, while security is guaranteed as long as at most $t < \frac{n}{2}$ parties are corrupted. Unfortunately, traditional threshold cryptosystems do not scale well, when executed at large-scale...
Onion routing (OR) protocols are a crucial tool for providing anonymous internet communication. An OR protocol enables a user to anonymously send requests to a server. A fundamental problem of OR protocols is how to deal with replies: ideally, we would want the server to be able to send a reply back to the anonymous user without knowing or disclosing the user's identity. Existing OR protocols do allow for such replies, but do not provably protect the payload (i.e., message) of replies...
Secure Multi-party Computation (MPC) allows to securely compute on private data. To make MPC practical, logic synthesis can be used to automatically translate a description of the function to be computed securely into optimized and error-free boolean circuits. TinyGMW (Demmler et al., CCS'15) used industry-grade hardware synthesis tools (DC, Yosys) to generate depth-optimized circuits for MPC. To evaluate their optimized circuits, they used the ABY framework (Demmler et al., NDSS'15) for...
Authenticated Key Exchange (AKE) protocols, by definition, guarantee both session key secrecy and entity authentication. Informally, session key secrecy means that only the legitimate parties learn the established key and mutual authentication means that one party can assure itself the session key is actually established with the other party. Today, an important application area for AKE is Internet of Things (IoT) systems, where an IoT device runs the protocol to establish a session key with...
Individual verifiability remains one of the main practical challenges in e-voting systems and, despite the central importance of this property, countries that sought to implement it faced repeated security problems. In this note, we revisit this property in the context of the IVXV version of the Estonian voting system, which has been in used for the Estonian municipal elections of 2017 and for the Estonian and European parliamentary elections of 2019. We show that a compromised voter...
Secure communication is an important aspect Internet of Things (IoT) applications in order to avoid cyber-security attacks and privacy issue. One of the key security aspects is data integrity, which can be protected by employing cryptographic hash functions. Recently, US National Institute of Standards and Technology (NIST) had initialized a competition to standardize lightweight hash functions targeting constrained devices, which can be used in IoT applications. The communication in IoT...
Blockchain as an enabler to current Internet infrastructure has provided many unique features and revolutionized current distributed systems into a new era. Its decentralization, immutability, and transparency have attracted many applications to adopt the design philosophy of blockchain and customize various replicated solutions. Under the hood of blockchain, consensus protocols play the most important role to achieve distributed replication systems. The distributed system community has...
Consider a scenario where Alice stores some secret data $s$ on $n$ servers using a $t$-out-of-$n$ secret sharing scheme. Trudy (the collector) is interested in the secret data of Alice and is willing to pay for it. Trudy publishes an advertisement on the internet which describes an elaborate cryptographic scheme to collect the shares from the $n$ servers. Each server who decides to submit its share is paid a hefty monetary reward and is guaranteed ``immunity" from being caught or prosecuted...
Digital signature schemes form the basis of trust in Internet communication. Shor (FOCS 1994) proposed quantum algorithms that can be used by a quantum computer to break the security of today’s widely used digital signature schemes, and this has fuelled intensive research on the design and implementation of post-quantum digital signatures. Hash-based digital signatures base their security on one-way functions that in practice are instantiated by hash functions. Hash-based signatures are...
While server-only authentication with certificates is the most widely used mode of operation for the Transport Layer Security (TLS) protocol on the world wide web, there are many applications where TLS is used in a different way or with different constraints. For example, embedded Internet-of-Things clients may have a server certificate pre-programmed and be highly constrained in terms of communication bandwidth or computation power. As post-quantum algorithms have a wider range of...
The proliferation of the Internet of Things (IoT) technology has made ubiquitous computing a reality by broadening Internet connectivity across diverse application domains, thus bridging billions of devices and human beings as well for information collection, data processing, and decision-making. In recent years, IoT technology and its applications in various industrial sectors have grown exponentially. Most existing industrial IoT (IIoT) implementations, however, are still relying on a...
Many interesting applications of pattern matching (e.g. deep-packet inspection or medical data analysis) target very sensitive data. In particular, spotting illegal behaviour in internet traffic conflicts with legitimate privacy requirements, which usually forces users (e.g. children, employees) to blindly trust an entity that fully decrypts their traffic in the name of security. The compromise between traffic analysis and privacy can be achieved through searchable encryption. However, as...
For applications of Byzantine fault tolerant (BFT) consensus protocols where the participants are economic agents, recent works highlighted the importance of accountability: the ability to identify participants who provably violate the protocol. At the same time, being able to reach consensus under dynamic levels of participation is desirable for censorship resistance. We identify an availability-accountability dilemma: in an environment with dynamic participation, no protocol can...
Distributed ledger technologies like blockchain have gained great attention in both academia and industry. Blockchain as a potentially disruptive technology can advance many different fields, e.g., cryptocurrencies, supply chains, and the industrial Internet of Things. The next-generation blockchain ecosystem is expected to consist of various homogeneous and heterogeneous distributed ledgers. These ledger systems will inevitably require a certain level of proper cooperation of multiple...
As people become more and more privacy conscious, the need for end-to-end encryption (E2EE) has become widely recognized. We study herein the security of SFrame, an E2EE mechanism recently proposed to the Internet Engineering Task Force for video/audio group communications over the Internet. Despite being a quite recent project, SFrame is going to be adopted by a number of real-world applications. We inspect the original specification of SFrame and find critical issues that will lead to...
This paper proposes a new ultra lightweight cipher RAGHAV. RAGHAV is a Substitution-Permutation (SP) network, which operates on 64 bit plaintext and supports a 128/80 bit key scheduling. It needs only 994.25 GEs by using 0.13µm ASIC technology for a 128 bit key scheduling. It also needs less memory i.e. 2204 bytes of FLASH memory , which is less as compared to all existing S-P network lightweight ciphers. This paper presents a complete security analysis of RAGHAV, which includes basic...
Edge computing and caching have emerged as key technologies in the future communication network to enhance the user experience, reduce backhaul traffic, and enable various Internet of Things applications. Different from conventional resources like CPU and memory that can be utilized by only one party at a time, a cached data item, which can be considered as a public good, can serve multiple parties simultaneously. Therefore, instead of independent caching, it is beneficial for the parties...
Mesh messaging applications allow users in relative proximity to communicate without the Internet. The most viable offering in this space, Bridgefy, has recently seen increased uptake in areas experiencing large-scale protests (Hong Kong, India, Iran, US, Zimbabwe, Belarus), suggesting its use in these protests. It is also being promoted as a communication tool for use in such situations by its developers and others. In this work, we report on a security analysis of Bridgefy. Our results...
Anonymous single-use tokens have seen recent applications in private Internet browsing and anonymous statistics collection. We develop new schemes in order to include public metadata such as expiration dates for tokens. This inclusion enables planned mass revocation of tokens without distributing new keys, which for natural instantiations can give 77 % and 90 % amortized traffic savings compared to Privacy Pass (Davidson et al., 2018) and DIT: De-Identified Authenticated Telemetry at Scale...
Alongside the development of cloud computing and Internet of Things(IoT), cloud-based RFID is receiving more attention nowadays. Cloud-based RFID system is specifically developed to providing real-time data that can be fed to the cloud for easy access and instant data interpretation. Security and privacy of constrained devices in these systems is a challenging issue for many applications. To deal with this problem, we propose \(\chi\)perbp, a lightweight authentication protocol based on...
A single-sign-on (SSO) is an authentication system that allows a user to log in with a single identity and password to any of several related, yet independent, server applications. SSO solutions eliminate the need for users to repeatedly prove their identities to different applications and hold different credentials for each application. Token-based authentication is commonly used to enable an SSO experience on the web, and on enterprise networks. A large body of work considers distributed...
In this report, we analyze the hardware implementations of 10 candidates for Round 2 of the NIST lightweight cryptography standardization process. These candidates are Ascon, DryGASCON, Elephant, Gimli, PHOTON-Beetle, Pyjamask, Romulus, Subterranean, TinyJAMBU and Xoodyak. Specifically, we study the implementations of these algorithms when synthesized using the TSMC 65nm and FDSOI 28nm technologies and Synopsys Design Compiler, targeting various performance trade-offs and different...
The security of digital communication relies on few cryptographic protocols that are used to protect internet traffic, from web sessions to instant messaging. These protocols and the cryptographic primitives they rely on have been extensively studied and are considered secure. Yet, sophisticated attackers are often able to bypass rather than break security mechanisms. Kleptography or algorithm substitution attacks (ASA) describe techniques to place backdoors right into cryptographic...
With the advances of Internet-of-Things (IoT) applications in smart cities and the pervasiveness of network devices with limited resources, lightweight block ciphers have achieved rapid development recently. Due to their relatively simple key schedule, nonlinear invariant attacks have been successfully applied to several families of lightweight block ciphers. This attack relies on the existence of a nonlinear invariant $g:\F_2^n \rightarrow \F_2$ for the round function $F_k$ so that $g(x)...
The connectivity is increasing in the world with the increased usage of IoT (Internet of Things) devices. To this end, amount of data that needs to be stored and retrieved securely has increased tremendously, but the IoT devices have a small amount of memory and computation capacity. Consequently, a storage area with a large amount of secured storage space is needed. Software-defined Networking (SDN) is an emerging network technology which implements a new paradigm of insecure applications...
With the emergence of the Industrial Internet of Things (IIoT), numerous operations based on smart devices contribute to producing convenience and comfortable applications for individuals and organizations. Considering the untrusted feature of the communication channels in IIoT, it is essential to ensure the authentication and incontestableness of the messages transmitted in the IIoT. In this paper, we firstly proposed a certificate-based parallel key-insulated aggregate signature...
Election verifiability aims to ensure that the outcome produced by electronic voting systems correctly reflects the intentions of eligible voters, even in the presence of an adversary that may corrupt various parts of the voting infrastructure. Protecting such systems from manipulation is challenging because of their distributed nature involving voters, election authorities, voting servers and voting platforms. An adversary corrupting any of these can make changes that, individually, would...
The lightweight block cipher PRESENT has become viable for areas like IoT (Internet of Things) and RFID tags, due to its compact design and low power consumption, while providing a sufficient level of security for the aforementioned applications. However, the key scheduling algorithm of a cipher plays a major role in deciding how secure it is. In this paper we test the strength of the key scheduling algorithm (KSA) of the 80-bit key length variant of PRESENT by attempting to retrieve the...
The industrial Internet of Things (IIoT) integrates sensors, instruments, equipment, and industrial applications, enabling traditional industries to automate and intelligently process data. To reduce the cost and demand of required service equipment, IIoT relies on cloud computing to further process and store data. Public-key encryption with keyword search (PEKS) plays an important role, due to its search functionality, to ensure the privacy and confidentiality of the outsourced data and the...
String search finds occurrences of patterns in a larger text. This general problem occurs in various application scenarios, f.e. Internet search, text processing, DNA analysis, etc. Using somewhat homomorphic encryption with SIMD packing, we provide an efficient string search protocol that allows to perform a private search in outsourced data with minimal preprocessing. At the base of the string search protocol lies a randomized homomorphic equality circuit whose depth is independent of the...
Abstract--- This paper demonstrates fast and compact implementations of Elliptic Curve Cryptography (ECC) for efficient key agreement over Curve25519. Curve25519 has been recently adopted as a key exchange method for several applications such as connected small devices as well as cloud, and included in the National Institute of Standards and Technology (NIST) recommendations for public key cryptography. This paper presents three different performance level designs including lightweight,...
Lightweight authenticated key exchange (AKE) protocols based on symmetric-key cryptography are important in securing the Internet of Things (IoT). However, achieving perfect forward secrecy (PFS) is not trivial for AKE based on symmetric-key cryptography, as opposed to AKE based on public-key cryptography. The most recent proposals that provide PFS are SAKE and SAKE-AM. In this paper, we first take a closer look at these protocols and observe that they have some limitations, specially when...
The Internet of Things (IoT) based services are getting a widespread expansion in all the directions and dimensions of the 21st century. The IoT based deployment involves an internet-connected sensor, mobiles, laptops, and other networking and computing de- vices. In most IoT based applications, the sensor collects the data and communicates it to the end-user via gateway device or fog device over a precarious internet channel. The attacker can use this open channel to capture the...
Cryptographic protections are ubiquitous in information technology, including the emerging Internet of Things (IoT). As a result of technology migration to a resource-challenged landscape and new threats to cryptographic security, governments and industry are exploring new cryptographic algorithms. While new standards will emerge, however, old standards will not disappear for the time being. It is therefore important to explore platforms where multiple cryptographic deployments can be...
Mass surveillance can be more easily achieved leveraging fear and desire of the population to feel protected while affected by devastating events. Indeed, in such scenarios, governments can adopt exceptional measures that limit civil rights, usually receiving large support from citizens. The COVID-19 pandemic is currently affecting daily life of many citizens in the world. People are forced to stay home for several weeks, unemployment rates quickly increase, uncertainty and sadness...
Physical Unclonable Functions (PUFs) provide means to generate chip individual keys, especially for low-cost applications such as the Internet of Things (IoT). They are intrinsically robust against reverse engineering, and more cost-effective than non-volatile memory (NVM). For several PUF primitives, countermeasures have been proposed to mitigate side-channel weaknesses. However, most mitigation techniques require substantial design effort and/or complexity overhead, which cannot be...
The absence of deployed vehicular communication systems, which prevents the advanced driving assistance systems (ADASs) and autopilots of semi/fully autonomous cars to validate their virtual perception regarding the physical environment surrounding the car with a third party, has been exploited in various attacks suggested by researchers. Since the application of these attacks comes with a cost (exposure of the attacker’s identity), the delicate exposure vs. application balance has held, and...
If two or more identical HTTPS clients, located at different geographic locations (regions), make an HTTPS request to the same domain (e.g. example.com), on the same day, will they receive the same HTTPS security guarantees in response? Our results give evidence that this is not always the case. We conduct scans for the top 250000 most visited domains on the Internet, from clients located at five different regions: Australia, Brazil, India, the UK, and the US. Our scans gather data from both...
As the need for lightweight cryptography has grown even more due to the evolution of the Internet of Things, it has become a greater challenge for cryptographers to design ultra lightweight stream ciphers in compliance with the rule of thumb that the internal state size should be at least twice as the key size to defend against generic Time-Memory-Data Tradeoff (TMDT) attacks. However, recently in 2015, Armknecht and Mikhalev sparked a new light on designing keystream generators (KSGs),...
The world has seen an influx of connected devices through both smart devices and smart cities, paving the path forward for the Internet of Things (IoT). These emerging intelligent infrastructures and applications based on IoT can be beneficial to users only if essential private and secure features are assured. However, with constrained devices being the norm in IoT, security and privacy are often minimized. In this paper, we first categorize various existing privacy-enhancing technologies...
We present a generalization of Maurer's unified zero-knowledge (UZK) protocol, namely a unified generic zero-knowledge (UGZK) construction. We prove the security of our UGZK protocol and discuss special cases. Compared to UZK, the new protocol allows to prove knowledge of a vector of secrets instead of only one secret. We also provide the reader with a hash variant of UGZK and the corresponding security analysis. Last but not least, we extend Cogliani \emph{et al.}'s lightweight...
Public key cryptography is threatened by the advent of quantum computers. Using Shor's algorithm on a large-enough quantum computer, an attacker can cryptanalyze any RSA/ECC public key, and generate fake digital signatures in seconds. If this vulnerability is left unaddressed, digital communications and electronic transactions can potentially be without the assurance of authenticity and non-repudiation. In this paper, we study the use of digital signatures in 14 real-world applications...
