Year: 2025
Type: conference-paper
Abstract: The medium-density parity-check (MDPC) code-based Bit Flipping Key Encapsulation (BIKE) mechanism remains a candidate for post-quantum cryptography standardization. The latest version utilizes a new bit-flipping (BF) decoding algorithm, which decides the BF threshold by an affine function with high-precision coefficients. Previous BF decoder implementations can be extended to the new algorithm. However, they suffer from large memories that dominate the overall complexity. This paper proposes a column-layered decoder for the new BIKE BF decoding algorithm to substantially reduce the memory requirement, and optimizes the affine BF threshold function coefficients to reduce the code length needed for the same security level. For the first time, our work also investigates the impact of finite precision representation of the threshold coefficients on the decoding performance. For an example MDPC code considered for the standard, the proposed layered BF decoder achieves 20% complexity reduction compared to the best prior effort with a very small latency overhead.
Authors: Jiaxuan Cai, Xinmiao Zhang
Institution: The Ohio State University
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
Funder: National Science Foundation
OpenAlex ID: W4411724809