Title:

Cache-Timing Attack Against HQC

 

Abstract:

HQC (Hamming Quasi-Cyclic) is a code-based post-quantum secure key encapsulation mechanism (KEM) that remains in the fourth round of the ongoing NIST Post-Quantum Cryptography standardization project. In this talk, I will present a chosen-ciphertext cache-timing attack on HQC. I will first introduce the concept of cache line indicator that describes timing behavior of the HQC implementation. This concept will be used to construct a cache-timing-based distinguisher to realize a plaintext-checking (PC) oracle. The PC oracle checks if a given ciphertext decrypts to a given message, which forms an essential part for a new full key-recovery attack that exploits the sparsity of the HQC key. To demonstrate the practicality of the proposed method, I will present the results of attacking HQC with Prime+Probe technique on an Intel SGX platform using the SGX-Step framework.

 

Bio:

Chitchanok Chuengsatiansup is a Senior Lecturer and a member of the Security Research Group at the School of Computing and Information Systems, The University of Melbourne, Australia. Her research aims at enhancing the security and efficiency of cryptosystems by considering the interplay among side-channel security, mathematical constructions, and users' performance budget.

 

Speaker:

Chitchanok Chuengsatiansup

Senior Lecturer
The University of Melbourne