Paper 2004/271

The Mundja Streaming MAC

Philip Hawkes and Michael Paddon and Gregory G. Rose

Abstract

Mundja is a MAC generation algorithm that has been designed for use together with a stream cipher. Mundja accumulates the message onto two independent registers: the first is a Cyclic Redundancy Checksum (CRC) that uses linear feedback; the second is a strengthened version of the SHA-256 register that uses nonlinear feedback. Mundja is fast (asymptotically about 4 times the speed of HMAC-SHA-256), and can generate MACs of any desired length. Mundja is designed to be secure at the equivalent level of 128-bit keys. When used in cooperation with a correspondingly secure stream cipher, it is hoped to remain secure even at the equivalent level of 256-bit keys. Appendices give details of the use of Mundja with the SOBER-128, Turing and RC4 stream ciphers.

Note: This paper was presented at the "SASC - The State of the Art of Stream Ciphers" workshop, Brugge, Belgium, October 14-15, 2004. The SASC workshop has no proceedings.