18 results sorted by ID
Possible spell-corrected query: Implementation attacks and defense
Leaking Secrets in Homomorphic Encryption with Side-Channel Attacks
Furkan Aydin, Aydin Aysu
Homomorphic encryption (HE) allows computing encrypted data in the ciphertext domain without knowing the encryption key. It is possible, however, to break fully homomorphic encryption (FHE) algorithms by using side channels. This article demonstrates side-channel leakages of the Microsoft SEAL HE library. The proposed attack can steal encryption keys during the key generation phase by abusing the leakage of ternary value assignments that occurs during the number theoretic transform (NTT)...
Automated Generation of Masked Nonlinear Components: From Lookup Tables to Private Circuits
Lixuan Wu, Yanhong Fan, Bart Preneel, Weijia Wang, Meiqin Wang
Implementation
Masking is considered to be an essential defense mechanism against side-channel attacks, but it is challenging to be adopted for hardware cryptographic implementations, especially for high security orders. Recently, Knichel et al. proposed an automated tool called AGEMA that enables the generation of masked implementations in hardware for arbitrary security orders using composable gadgets. This accelerates the construction and practical application of masking schemes. This article proposes a...
Apple vs. EMA: Electromagnetic Side Channel Attacks on Apple CoreCrypto
Gregor Haas, Aydin Aysu
Implementation
Cryptographic instruction set extensions are commonly used for ciphers which would otherwise face unacceptable side channel risks. A prominent example of such an extension is the ARMv8 Cryptographic Extension, or ARM CE for short, which defines dedicated instructions to securely accelerate AES. However, while these extensions may be resistant to traditional "digital" side channel attacks, they may still vulnerable to physical side channel attacks.
In this work, we demonstrate the first such...
RevEAL: Single-Trace Side-Channel Leakage of the SEAL Homomorphic Encryption Library
Furkan Aydin, Emre Karabulut, Seetal Potluri, Erdem Alkim, Aydin Aysu
This paper demonstrates the first side-channel attack on homomorphic encryption (HE), which allows computing on encrypted data. We reveal a power-based side-channel leakage of Microsoft SEAL prior to v3.6 that implements the Brakerski/Fan-Vercauteren (BFV) protocol. Our proposed attack targets the Gaussian sampling in the SEAL’s encryption phase and can extract the entire message with a single power measurement.
Our attack works by (1) identifying each coefficient index being sampled, (2)...
SeqL+: Secure Scan-Obfuscation with Theoretical and Empirical Validation
Seetal Potluri, Shamik Kundu, Akash Kumar, Kanad Basu, Aydin Aysu
Implementation
Existing logic-locking attacks are known to successfully decrypt a functionally correct key of a locked combinational
circuit. Extensions of these attacks to real-world Intellectual Properties (IPs, which are sequential circuits) have been demonstrated through the scan-chain by selectively initializing the combinational logic and analyzing the responses. In this paper, we propose SeqL+ to mitigate a broad class of such attacks. The key idea is to lock selective functional-input/scan-output...
Breaking CAS-Lock and Its Variants by Exploiting Structural Traces
Abhrajit Sengupta, Nimisha Limaye, Ozgur Sinanoglu
Implementation
Logic locking is a prominent solution to protect against design intellectual property theft. However, there has been a decade-long cat-and-mouse game between defenses and attacks. A turning point in logic locking was the development of miter-based Boolean satisfiability (SAT) attack that steered the research in the direction of developing SAT-resilient schemes. These schemes, however achieved SAT resilience at the cost of low output corruption. Recently, cascaded locking (CAS-Lock) was...
Attacking Zcash For Fun And Profit
Duke Leto, The Hush Developers
Implementation
This paper will outline, for the first time, exactly how the ITM Attack (a linkability attack against
shielded transactions) works against Zcash Protocol and how Hush is the first cryptocoin with a defensive mitigation against it, called ”Sietch ”. Sietch is already running live in production and undergoing
rounds of improvement from expert feedback. This is not an academic paper about pipedreams. It
describes production code and networks.
We begin with a literature review of all known...
Custom Instruction Support for Modular Defense against Side-channel and Fault Attacks
Pantea Kiaei, Darius Mercadier, Pierre-Evariste Dagand, Karine Heydemann, Patrick Schaumont
Implementation
The design of software countermeasures against active and passive adversaries is a challenging problem that has been addressed by many authors in recent years. The proposed solutions adopt a theoretical foundation (such as a leakage model) but often do not offer concrete reference implementations to validate the foundation. Contributing to the experimental dimension of this body of work, we propose a customized processor called SKIVA that supports experiments with the design of...
On the Difficulty of FSM-based Hardware Obfuscation
Marc Fyrbiak, Sebastian Wallat, Jonathan Déchelotte, Nils Albartus, Sinan Böcker, Russell Tessier, Christof Paar
Implementation
In today’s Integrated Circuit (IC) production chains, a designer’s valuable Intellectual Property (IP) is transparent to diverse stakeholders and thus inevitably prone to piracy. To protect against this threat, numerous defenses based on the obfuscation of a circuit’s control path, i.e. Finite State Machine (FSM), have been proposed and are commonly believed to be secure. However, the security of these sequential obfuscation schemes is doubtful since realistic capabilities of reverse...
SEAL: Attack Mitigation for Encrypted Databases via Adjustable Leakage
Ioannis Demertzis, Dimitrios Papadopoulos, Charalampos Papamanthou, Saurabh Shintre
Cryptographic protocols
Building expressive encrypted databases that can scale to large volumes of data while enjoying formal security guarantees has been one of the holy grails of security and cryptography research. Searchable Encryption (SE) is considered to be an attractive implementation choice for this goal: It naturally supports basic database queries such as point, join and range, and is very practical at the expense of well-defined leakage such as search and access pattern. Nevertheless, recent attacks have...
Dragonblood: Analyzing the Dragonfly Handshake of WPA3 and EAP-pwd
Mathy Vanhoef, Eyal Ronen
Cryptographic protocols
We systematically analyze WPA3 and EAP-pwd, find denial-of-service and downgrade attacks, present severe vulnerabilities in all implementations, reveal side-channels that enable offline dictionary attacks, and propose design fixes which are being officially adopted.
The WPA3 certification aims to secure home networks, while EAP-pwd is used by certain enterprise Wi-Fi networks to authenticate users. Both use the Dragonfly handshake to provide forward secrecy and resistance to dictionary...
Complete Attack on RLWE Key Exchange with reused keys, without Signal Leakage
Jintai Ding, Scott Fluhrer, Saraswathy RV
Key Exchange (KE) from RLWE (Ring-Learning with Errors) is a potential alternative to Diffie-Hellman (DH) in a post quantum setting. Key leakage with RLWE key exchange protocols in the context of key reuse has already been pointed out in previous work. The initial attack described by Fluhrer is designed in such a way that it only works on Peikert's KE protocol and its variants that derives the shared secret from the most significant bits of the approximately equal keys computed by both...
Differential Attacks on Deterministic Signatures
Christopher Ambrose, Joppe W. Bos, Björn Fay, Marc Joye, Manfred Lochter, Bruce Murray
Public-key cryptography
Deterministic signature schemes are becoming more popular, as illustrated by the deterministic variant of ECDSA and the popular EdDSA scheme, since eliminating the need for high-quality randomness might have some advantages in certain use-cases. In this paper we outline a range of differential fault attacks and a differential power analysis attack against such deterministic schemes. This shows, contrary to some earlier works, that such signature schemes are not naturally protected against...
Performance Counters to Rescue: A Machine Learning based safeguard against Micro-architectural Side-Channel-Attacks
Manaar Alam, Sarani Bhattacharya, Debdeep Mukhopadhyay, Sourangshu Bhattacharya
Micro-architectural side-channel-attacks are presently daunting threats to most mathematically elegant encryption algorithms. Even though there exist various defense mechanisms, most of them come with the extra overhead of implementation. Recent studies have prevented some particular categories of these attacks but fail to address the detection of other classes. This paper presents a generic machine learning based multi-layer detection approach targeting these micro-architectural...
Statistical Analysis for Access-Driven Cache Attacks Against AES
Liwei Zhang, A. Adam Ding, Yunsi Fei, Zhen Hang Jiang
In recent years, side-channel timing attacks utilizing architectural behavior have been applied to cloud settings, presenting a realistic and serious cyber threat. Access-driven cache attacks allow the adversary to observe side-channel leakage (cache access pattern) of a critical cryptographic implementation to infer the secret key. However, what the attackers observe may deviate from the real cache footprint of the victim process, affecting the effectiveness of cache-based timing attacks...
Post-quantum key exchange - a new hope
Erdem Alkim, Léo Ducas, Thomas Pöppelmann, Peter Schwabe
Public-key cryptography
In 2015, Bos, Costello, Naehrig, and Stebila (IEEE Security & Privacy 2015)
proposed an instantiation of Ding's ring-learning-with-errors (Ring-LWE) based
key-exchange protocol (also including the tweaks proposed by Peikert from
PQCrypto 2014), together with an implementation integrated into OpenSSL, with
the affirmed goal of providing post-quantum security for TLS.
In this work we revisit their instantiation and stand-alone implementation.
Specifically, we propose new parameters and a...
Power Analysis Attacks against FPGA Implementations of KLEIN
Shaohua Tang, Jianhao Wu, Weijian Li, Zheng Gong
Secret-key cryptography
KLEIN is a family of block ciphers proposed by Zheng Gong et al. at RFIDSec 2011, and its lightweight features are suitable for resource-constrained devices. However, the original design of KLEIN does not consider the potential attacks by power analysis methods. This paper presents power analysis attacks against a FPGA implementation of KLEIN by the authors of KLEIN. The attacking strategy, attacking point and complexity of our attacks via power analysis against KLEIN are discussed in...
Garbled Circuits for Leakage-Resilience: Hardware Implementation and Evaluation of One-Time Programs
Kimmo Järvinen, Vladimir Kolesnikov, Ahmad-Reza Sadeghi, Thomas Schneider
The power of side-channel leakage attacks on cryptographic implementations is evident.
Today's practical defenses are typically attack-specific countermeasures against certain classes of side-channel attacks.
The demand for a more general solution has given rise to the recent theoretical research that aims to build provably leakage-resilient cryptography.
This direction is, however, very new and still largely lacks practitioners' evaluation with regard to both efficiency and practical...
Homomorphic encryption (HE) allows computing encrypted data in the ciphertext domain without knowing the encryption key. It is possible, however, to break fully homomorphic encryption (FHE) algorithms by using side channels. This article demonstrates side-channel leakages of the Microsoft SEAL HE library. The proposed attack can steal encryption keys during the key generation phase by abusing the leakage of ternary value assignments that occurs during the number theoretic transform (NTT)...
Masking is considered to be an essential defense mechanism against side-channel attacks, but it is challenging to be adopted for hardware cryptographic implementations, especially for high security orders. Recently, Knichel et al. proposed an automated tool called AGEMA that enables the generation of masked implementations in hardware for arbitrary security orders using composable gadgets. This accelerates the construction and practical application of masking schemes. This article proposes a...
Cryptographic instruction set extensions are commonly used for ciphers which would otherwise face unacceptable side channel risks. A prominent example of such an extension is the ARMv8 Cryptographic Extension, or ARM CE for short, which defines dedicated instructions to securely accelerate AES. However, while these extensions may be resistant to traditional "digital" side channel attacks, they may still vulnerable to physical side channel attacks. In this work, we demonstrate the first such...
This paper demonstrates the first side-channel attack on homomorphic encryption (HE), which allows computing on encrypted data. We reveal a power-based side-channel leakage of Microsoft SEAL prior to v3.6 that implements the Brakerski/Fan-Vercauteren (BFV) protocol. Our proposed attack targets the Gaussian sampling in the SEAL’s encryption phase and can extract the entire message with a single power measurement. Our attack works by (1) identifying each coefficient index being sampled, (2)...
Existing logic-locking attacks are known to successfully decrypt a functionally correct key of a locked combinational circuit. Extensions of these attacks to real-world Intellectual Properties (IPs, which are sequential circuits) have been demonstrated through the scan-chain by selectively initializing the combinational logic and analyzing the responses. In this paper, we propose SeqL+ to mitigate a broad class of such attacks. The key idea is to lock selective functional-input/scan-output...
Logic locking is a prominent solution to protect against design intellectual property theft. However, there has been a decade-long cat-and-mouse game between defenses and attacks. A turning point in logic locking was the development of miter-based Boolean satisfiability (SAT) attack that steered the research in the direction of developing SAT-resilient schemes. These schemes, however achieved SAT resilience at the cost of low output corruption. Recently, cascaded locking (CAS-Lock) was...
This paper will outline, for the first time, exactly how the ITM Attack (a linkability attack against shielded transactions) works against Zcash Protocol and how Hush is the first cryptocoin with a defensive mitigation against it, called ”Sietch ”. Sietch is already running live in production and undergoing rounds of improvement from expert feedback. This is not an academic paper about pipedreams. It describes production code and networks. We begin with a literature review of all known...
The design of software countermeasures against active and passive adversaries is a challenging problem that has been addressed by many authors in recent years. The proposed solutions adopt a theoretical foundation (such as a leakage model) but often do not offer concrete reference implementations to validate the foundation. Contributing to the experimental dimension of this body of work, we propose a customized processor called SKIVA that supports experiments with the design of...
In today’s Integrated Circuit (IC) production chains, a designer’s valuable Intellectual Property (IP) is transparent to diverse stakeholders and thus inevitably prone to piracy. To protect against this threat, numerous defenses based on the obfuscation of a circuit’s control path, i.e. Finite State Machine (FSM), have been proposed and are commonly believed to be secure. However, the security of these sequential obfuscation schemes is doubtful since realistic capabilities of reverse...
Building expressive encrypted databases that can scale to large volumes of data while enjoying formal security guarantees has been one of the holy grails of security and cryptography research. Searchable Encryption (SE) is considered to be an attractive implementation choice for this goal: It naturally supports basic database queries such as point, join and range, and is very practical at the expense of well-defined leakage such as search and access pattern. Nevertheless, recent attacks have...
We systematically analyze WPA3 and EAP-pwd, find denial-of-service and downgrade attacks, present severe vulnerabilities in all implementations, reveal side-channels that enable offline dictionary attacks, and propose design fixes which are being officially adopted. The WPA3 certification aims to secure home networks, while EAP-pwd is used by certain enterprise Wi-Fi networks to authenticate users. Both use the Dragonfly handshake to provide forward secrecy and resistance to dictionary...
Key Exchange (KE) from RLWE (Ring-Learning with Errors) is a potential alternative to Diffie-Hellman (DH) in a post quantum setting. Key leakage with RLWE key exchange protocols in the context of key reuse has already been pointed out in previous work. The initial attack described by Fluhrer is designed in such a way that it only works on Peikert's KE protocol and its variants that derives the shared secret from the most significant bits of the approximately equal keys computed by both...
Deterministic signature schemes are becoming more popular, as illustrated by the deterministic variant of ECDSA and the popular EdDSA scheme, since eliminating the need for high-quality randomness might have some advantages in certain use-cases. In this paper we outline a range of differential fault attacks and a differential power analysis attack against such deterministic schemes. This shows, contrary to some earlier works, that such signature schemes are not naturally protected against...
Micro-architectural side-channel-attacks are presently daunting threats to most mathematically elegant encryption algorithms. Even though there exist various defense mechanisms, most of them come with the extra overhead of implementation. Recent studies have prevented some particular categories of these attacks but fail to address the detection of other classes. This paper presents a generic machine learning based multi-layer detection approach targeting these micro-architectural...
In recent years, side-channel timing attacks utilizing architectural behavior have been applied to cloud settings, presenting a realistic and serious cyber threat. Access-driven cache attacks allow the adversary to observe side-channel leakage (cache access pattern) of a critical cryptographic implementation to infer the secret key. However, what the attackers observe may deviate from the real cache footprint of the victim process, affecting the effectiveness of cache-based timing attacks...
In 2015, Bos, Costello, Naehrig, and Stebila (IEEE Security & Privacy 2015) proposed an instantiation of Ding's ring-learning-with-errors (Ring-LWE) based key-exchange protocol (also including the tweaks proposed by Peikert from PQCrypto 2014), together with an implementation integrated into OpenSSL, with the affirmed goal of providing post-quantum security for TLS. In this work we revisit their instantiation and stand-alone implementation. Specifically, we propose new parameters and a...
KLEIN is a family of block ciphers proposed by Zheng Gong et al. at RFIDSec 2011, and its lightweight features are suitable for resource-constrained devices. However, the original design of KLEIN does not consider the potential attacks by power analysis methods. This paper presents power analysis attacks against a FPGA implementation of KLEIN by the authors of KLEIN. The attacking strategy, attacking point and complexity of our attacks via power analysis against KLEIN are discussed in...
The power of side-channel leakage attacks on cryptographic implementations is evident. Today's practical defenses are typically attack-specific countermeasures against certain classes of side-channel attacks. The demand for a more general solution has given rise to the recent theoretical research that aims to build provably leakage-resilient cryptography. This direction is, however, very new and still largely lacks practitioners' evaluation with regard to both efficiency and practical...
