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
-
Chamois: Formally verified compilation for optimisation and security
Speaker : David MONNIAUX - CNRS - Verimag
Embedded programs (including those on smart cards) are often developed in C and then compiled for the embedded processor. Sometimes they are modified by hand to incorporate countermeasures (fault attacks, etc.), but care must be taken to ensure that this does not disrupt normal program execution and that the countermeasure is actually adequate for blocking the attacks.In the process, it is[…]-
SemSecuElec
-
Fault injection
-
Formal methods
-
-
Security of Smart Dust: Robust Key Derivation for Single-Chip Systems
Speaker : Sara Faour - Inria
The Smart Dust vision seeks to enable large networks of millimeter-scale wireless sensor nodes that tightly integrate sensing, computation, communication, and power management into a single-chip device. Establishing a robust hardware root of trust for such devices remains challenging, particularly in single, low-cost chip manufacturing processes that lack embedded writable Non-Volatile Memory (NVM[…] -
Securing processor's microarchitecture against SCA in a post-quantum cryptography setting
Speaker : Vincent MIGLIORE - LAAS-CNRS
Hardware microarchitecture is a well-known source of side-channel leakages, providing a notable security reduction of standard cryptographic algorithms (e.g. AES) if not properly addressed by software or hardware. In this talk, we present new design approaches to harden processor's microarchitecture against power-based side-channel attacks, relying on configurable and cascadable building blocks[…]-
SemSecuElec
-
Side-channel
-
Micro-architectural vulnerabilities
-
-
Onysis: A secure European SoC FPGA
Speaker : Adrien GRASSEIN - Nanoxplore
Developed in collaboration with the DGA, the Onysis project introduces a European SoC FPGA designed to embed advanced hardware security features. This presentation will provide an overview of the Onysis architecture, focusing specifically on its native mechanisms to protect critical systems. We will detail the implementation of its integrated security subsystem, covering the secure boot sequence[…]-
SemSecuElec
-