TMAC: Two-Key CBC MAC

Kaoru Kurosawa; Tetsu Iwata

Paper 2002/092

TMAC: Two-Key CBC MAC

Kaoru Kurosawa and Tetsu Iwata

Abstract

In this paper, we propose TMAC, Two-Key CBC Message Authentication Code. TMAC is a refinement of XCBC (which is a variant of CBC MAC) shown by Black and Rogaway. We use only $(k + n)$ -bit key for TMAC while XCBC uses $(k + 2 n)$ -bit key, where $k$ is the key length of the underlying block cipher and $n$ is its block length. The cost for reducing the size of secret keys is almost negligible; only one shift and one conditional XOR. Similarly to XCBC, our algorithm correctly and efficiently handles messages of arbitrary bit length.

Metadata

Available format(s): PDF PS
Category: Secret-key cryptography
Publication info: Published elsewhere. NIST submission
Keywords: AES secret-key cryptography message authentication codes
Contact author(s): iwata @ cis ibaraki ac jp
History: 2002-07-11: revised; 2002-07-10: received; See all versions
Short URL: https://ia.cr/2002/092
License: CC BY

BibTeX

@misc{cryptoeprint:2002/092,
      author = {Kaoru Kurosawa and Tetsu Iwata},
      title = {{TMAC}: Two-Key {CBC} {MAC}},
      howpublished = {Cryptology {ePrint} Archive, Paper 2002/092},
      year = {2002},
      url = {https://eprint.iacr.org/2002/092}
}