Keyed Streebog is a secure PRF and MAC

Vitaly Kiryukhin

Paper 2022/972

Keyed Streebog is a secure PRF and MAC

Vitaly Kiryukhin, LLC "SFB Lab", Moscow, Russia, JSC "InfoTeCS", Moscow, Russia

Abstract

One of the most popular ways to turn a keyless hash function into a keyed one is the HMAC algorithm. This approach is too expensive in some cases due to double hashing. Excessive overhead can sometimes be avoided by using certain features of the hash function itself. The paper presents a simple and safe way to create a keyed cryptoalgorithm (conventionally called "Streebog-K") from hash function Streebog $\mathsf{H}(M)$. Let $K$ be a secret key, then $\mathsf{KH}(K,M)=\mathsf{H}(K||M)$ is a secure pseudorandom function (PRF) and, therefore, a good message authentification code (MAC). The proof is obtained by reduction of the security of the presented construction to the resistance of the underlying compression function to the related key attacks (PRF-RKA). The security bounds of Streebog-K are essentially the same as those of HMAC-Streebog, but the computing speed doubles when short messages are used.

Metadata

Available format(s): PDF
Category: Secret-key cryptography
Publication info: Published elsewhere. CTCrypt 2022 - 11th Workshop on Current Trends in Cryptology, June 6–9, 2022, Novosibirsk, Russia
Keywords: Streebog Streebog-K PRF MAC HMAC provable security
Contact author(s): vitaly kiryukhin @ sfblaboratory ru
History: 2022-07-30: approved; 2022-07-29: received; See all versions
Short URL: https://ia.cr/2022/972
License: CC BY

BibTeX

@misc{cryptoeprint:2022/972,
      author = {Vitaly Kiryukhin},
      title = {Keyed Streebog is a secure {PRF} and {MAC}},
      howpublished = {Cryptology {ePrint} Archive, Paper 2022/972},
      year = {2022},
      url = {https://eprint.iacr.org/2022/972}
}