On the Internal Structure of ALPHA-MAC

Authors

J. Huang, University of WollongongFollow
Jennifer Seberry, University of WollongongFollow
Willy Susilo, University of WollongongFollow

RIS ID

15715

Publication Details

This paper was originally published as Huang, J., Seberry, J., and Susilo, W., On the Internal Structure of ALPHA-MAC, Vietcrypt'06 International Conference on Cryptology, 2006, 271-285.

Abstract

ALPHA-MAC is a MAC function which uses the building blocks of AES. This paper studies the internal structure of this new design. First, we provide a method to find second preimages based on the assumption that a key or an intermediate value is known. The proposed searching algorithm exploits the algebraic properties of the underlying block cipher and needs to solve eight groups of linear functions to find a second preimage. Second, we show that our idea can also be used to find internal collisions under the same assumption. We do not make any claims that those findings in any way endanger the security of this MAC function. Our contribution is showing how algebraic properties of AES can be used for analysis of this MAC function.