A Configurable Crystals-Kyber Hardware Implementation with Side-Channel Protection.

In this work, we present a configurable and side channel resistant implementation of the post-quantum key-exchange algorithm CRYSTALS-Kyber . The implemented design can be configured for different performance and area requirements leading to different trade-offs for different applications. A low area implementation can be achieved in 5269 LUTs and 2422 FFs, whereas a high performance implementation required 7151 LUTs and 3730 FFs. Due to a deeply pipelined architecture, a high operating speed of more than 250 MHz could be achieved on 28nm Xilinx FPGAs. The side channel resistance is implemented using a carefully chosen set of novel and known techniques such as Fault Detection Hashes, Instruction Randomization, FSM Protection etc. resulting in a low overhead of less than \(5\% \) while being highly configurable. To the best of our knowledge, this work presents the first side-channel and fault attack protected configurable accelerator for CRYSTALS-Kyber . Using TVLA (test vector leakage assessment), we validate the implemented protection techniques and demonstrate that the design does not leak information even after 200K traces. Furthermore, one of the configuration choices results in the smallest hardware implementation of CRYSTALS-Kyber known in literature.