English

Perfect message authentication codes are robust to small deviations from uniform key distributions

Cryptography and Security 2025-08-14 v1

Abstract

We investigate the impact of (possible) deviations of the probability distribution of key values from a uniform distribution for the information-theoretic strong, or perfect, message authentication code. We found a simple expression for the decrease in security as a function of the statistical distance between the real key probability distribution and the uniform one. In a sense, a perfect message authentication code is robust to small deviations from a uniform key distribution.

Keywords

Cite

@article{arxiv.2508.09783,
  title  = {Perfect message authentication codes are robust to small deviations from uniform key distributions},
  author = {Boris Ryabko},
  journal= {arXiv preprint arXiv:2508.09783},
  year   = {2025}
}
R2 v1 2026-07-01T04:48:06.560Z