Description
Microarchitectural side-channel attacks can derive secrets from the execution of vulnerable programs. Their implementation in web browsers represents a considerable extension of their attack surface, as a user simply browsing a malicious website, or even a malicious third-party advertisement in a benign cross-origin isolated website, can be a victim.In this talk, we present the first CPU port contention side channel running entirely in a web browser, despite a highly challenging environment. Our attack can be used to build a cross-browser covert channel with a bit rate of 200bps, one order of magnitude above the state of the art, and has a spatial resolution of 1024 native instructions in a side-channel attack, a performance on-par with Prime+Probe attacks. We provide a framework to evaluate the port contention caused by WebAssembly instructions on Intel processors, allowing to increase the portability of port contention side channels. We conclude from our work that port contention attacks are not only fast, they are also less susceptible to noise than cache attacks, and are immune to countermeasures implemented in browsers as well as most side channel countermeasures, which target the cache in their vast majority.
Practical infos
Next sessions
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[CANCELLED] Black-Box Collision Attacks on Widely Deployed Perceptual Hash Functions and Their Consequences
Speaker : Diane Leblanc-Albarel - KU Leuven
[CANCELLED] Perceptual hash functions identify multimedia content by mapping similar inputs to similar outputs. They are widely used for detecting copyright violations and illegal content but lack transparency, as their design details are typically kept secret. Governments are considering extending the application of these functions to Client-Side Scanning (CSS) for end-to-end encrypted services:[…]-
Cryptography
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SoSysec
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Protocols
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A non-comparison oblivious sort and its application to private k-NN
Speaker : Sofiane Azogagh - UQÀM
Sorting is a fundamental subroutine of many algorithms and as such has been studied for decades. A well-known result is the Lower Bound Theorem, which states that no comparison-based sorting algorithm can do better than O(nlog(n)) in the worst case. However, in the fifties, new sorting algorithms that do not rely on comparisons were introduced such as counting sort, which can run in linear time[…]-
Cryptography
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SoSysec
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Privacy
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Databases
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Secure storage
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