Paper 2020/897

Folding BIKE: Scalable Hardware Implementation for Reconfigurable Devices

Jan Richter-Brockmann and Tim Güneysu

Abstract

In our daily lives we constantly use and trust Public-Key Cryptography to exchange keys over insecure communication channels. With the development and progress in the research field of quantum computers, well established schemes like RSA and ECC are more and more threatened. The urgent demand to find and standardize new schemes – which are secure in a post-quantum world – was also realized by the National Institute of Standards and Technology which announced a Post-Quantum Cryptography Standardization Project in 2017. Currently, this project is in the third round and one of the submitted candidates is the Key Encapsulation Mechanism scheme BIKE. In this work we investigate different strategies to efficiently implement the BIKE algorithm on FPGAs. To this extend, we improve already existing polynomial multipliers, propose efficient strategies to realize polynomial inversions, and implement the Black-Gray-Flip decoder for the first time. Additionally, our implementation is designed to be scalable and generic with the BIKE specific parameters. All together, the fastest designs achieve latencies of 2.69 ms for the key generation, 0.1 ms for the encapsulation, and 104.04 ms for the decapsulation considering the first security level.