Power Side-Channel Key Recovery Attack on a Hardware Implementation of BIKE

BIKE is a code-based Key Encapsulation Mechanism (KEM) currently under consideration for standardization by the National Institute of Standards and Technology (NIST). BIKE, along with several other candidates, is being evaluated in the fourth round of the NIST Post-Quantum Cryptography (PQC) competition. In comparison to the lattice-based candidates, relatively little effort has been focused on analyzing this algorithm for side-channel vulnerabilities, especially in hardware. There have been several works on side-channel attacks and countermeasures on software implementations of BIKE, but as of yet, there have been no works focused on hardware. This work presents the first side-channel attack on a hardware implementation of BIKE. The attack targets a public implementation of the algorithm and is able to fully recover the long-term secret key with only several dozen traces. This work reveals BIKE's significant susceptibilities to side-channel attacks when implemented in hardware and the need for investigation of hardware countermeasures.