Description
Caches leak information through timing measurements and so-called side-channel attacks. Several primitives exist with different requirements and trade-offs. Flush+Flush is a stealthy and fast cache attack primitive that uses the timing of the clflush instruction depending on the presence of a line in the cache. However, the CPU interconnect plays a bigger role than thought in these timings, and therefore in the error rate of Flush+Flush.
In this paper, we show that a naive implementation that does not take into account the topology of the interconnect yields very important error rates, especially on modern CPUs as the number of cores increases. We, therefore, reverse-engineer this topology and revisit the calibration phase of Flush+Flush for different attacker models to determine the correct threshold for clflush hits and misses. We evaluate that our method yields noiseless side-channel attacks by attacking the AES T-tables implementation of OpenSSL, and by building a covert channel. We obtain a maximal capacity of 3.15 Mbit/s with our improved method, compared to 1.4 Mbit/s with a naive implementation of Flush+Flush on an Intel Core i9-9900 CPU.
Next sessions
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Cryptanalytical extraction of complex Neural Networks in black-box settings
Speaker : Benoit COQUERET - INRIA, Thales CESTI
With the widespread development of artifical intelligence, Deep Neural Networks (DNN) have become valuable intellectual property (IP). In the past few years, software and hardware-based attacks targetting at the weights of the DNN have been introduced allowing potential attacker to gain access to a near-perfect copy of the victim's model. However, these attacks either fail against more complex[…]-
SemSecuElec
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Side-channel
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Machine learning
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Advanced techniques for fault injection attacks on integrated circuits
Speaker : Paul Grandamme - Laboratoire Hubert Curien, Université Jean Monnet
The security of integrated circuits is evaluated through the implementation of attacks that exploit their inherent hardware vulnerabilities. Fault injection attacks represent a technique that is commonly employed for this purpose. These techniques permit an attacker to alter the nominal operation of the component in order to obtain confidential information. Firstly, we propose the utilisation of[…]-
SemSecuElec
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Fault injection
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PHOENIX: Crypto-Agile Hardware Sharing for ML-KEM and HQC, hardware implementation of a PQC accelerator
Speaker : Antonio RAS
The security of the public-key cryptography protecting today and tomorrow’s communication is threatened by the advent of quantum computers. The transition to quantum-safe algorithms has begun: NIST has already standardized ML-KEM, a lattice-based KEM, and marked three code-based KEMs, including HQC, as alternatives for possible future standardization. The relative immaturity of all of these[…]-
Cryptography
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SemSecuElec
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Hardware accelerator
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Anomalies Mitigation for Horizontal Side Channel Attacks with Unsupervised Neural Networks
Speaker : Gauthier Cler - SERMA Safety & Security
The success of horizontal side-channel attacks heavily depends on the quality of the traces as well as the correct extraction of interest areas, which are expected to contain relevant leakages. If former is insufficient, this will consequently degrade the identification capability of potential leakage candidates and often render attacks inapplicable. This work assess the relevance of neural[…]-
SemSecuElec
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Side-channel
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Machine learning
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Side-Channel Based Disassembly on Complex Processors: From Microachitectural Characterization to Probabilistic Models
Speaker : Julien Maillard - CEA
Side-Channel Based Disassembly (SCBD) is a category of Side-Channel Analysis (SCA) that aims at recovering information on the code executed by a processor through the observation of physical side-channels such as power consumption or electromagnetic radiations. While traditional SCA often targets cryptographic keys, SCBD focuses on retrieving assembly code that can hardly be extracted via other[…]-
SemSecuElec
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Side-channel
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Hardware reverse
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