Paper 2019/1423
QC-MDPC decoders with several shades of gray
Nir Drucker and Shay Gueron and Dusan Kostic
Abstract
QC-MDPC code-based KEMs rely on decoders that have a small or even negligible Decoding Failure Rate (DFR). These decoders should be efficient and implementable in constant-time. One example for a QC-MDPC KEM is the Round-2 candidate of the NIST PQC standardization project, "BIKE". We have recently shown that the Black-Gray decoder achieves the required properties. In this paper, we deffine several new variants of the Black-Gray decoder. One of them, called Black-Gray-Flip, needs only 7 steps to achieve a smaller DFR than Black-Gray with 9 steps, for the same block size. On current AVX512 platforms, our BIKE-1 (Level-1) constant-time decapsulation is 1:9x faster than the previous decapsulation with Black-Gray. We also report an additional 1:25x decapsulating speedup using the new AVX512-VBMI2 and vector-PCLMULQDQ instructions available on "Ice-Lake" micro-architecture.
Metadata
- Available format(s)
- Category
- Public-key cryptography
- Publication info
- Preprint. MINOR revision.
- Keywords
- BIKEQC-MDPC codesconstant-time implementationQC-MDPC decoders
- Contact author(s)
- drucker nir @ gmail com,shay gueron @ gmail com,dusan kostic @ epfl ch
- History
- 2019-12-10: received
- Short URL
- https://ia.cr/2019/1423
- License
-
CC BY