A Comparison of Code-Based Cryptosystems

Abstract

The NIST PQC Standardization Process aims to find new cryptographic standards resistant to both classical and quantum computers. Several categories of cryptographic schemes are currently being evaluated by both NIST and the cryptographic community. Schemes are compared against one another with an emphasis on security, run-time performance, and bandwidth. A select few have made it to the third round and NIST hopes to standardize a subset of the schemes after the third round has come to an end. This research paper evaluates the encryption schemes of one of the five categories, code-based cryptography. Classic McEliece is a finalist and its security proof is strong, as its underlying mathematical concepts have been studied for over 40 years. Having said that, its large public key size makes it useful for only specific use cases. For general use, BIKE may be a better option, as its quasi-cyclic codes lead to a significant reduction in bandwidth. They will need to further analyze their decoding failure rate to ensure it is low enough to claim the required security level. Other metrics such as the rank-metric have also been considered. While they offer promising key sizes, further research into potential attacks is needed.