Cache-timing attack against HQC

ePrint Report: Cache-timing attack against HQC

Senyang Huang, Rui Qi Sim, Chitchanok Chuengsatiansup, Qian Guo, Thomas Johansson

In this paper, we present the first chosen-ciphertext (CC) cache-timing attacks on the reference implementation of HQC.
We build a cache-timing based distinguisher for implementing a plaintext-checking (PC) oracle. The PC oracle uses side-channel information to check if a given ciphertext decrypts to a given message.
This is done by identifying a vulnerability during the generating process of two vectors in the reference …

attack attacks build cache channel check ciphertext eprint report information message oracle plaintext process reference report side-channel sim thomas timing attack vulnerability