Cryptanalysis of an authentication scheme using truncated polynomials

Abstract

An attack on a recently proposed authentication scheme of Shpilrain and Ushakov is presented. The public information allows the derivation of a system of polynomial equations for the secret key bits. Our attack uses simple elimination techniques to distill linear equations. For the proposed parameter choice, the attack often finds secret keys or alternative secret keys within minutes with moderate resources. © 2009 Elsevier B.V. All rights reserved.