Cryptanalysing variants of Stickel's key agreement scheme
Ciarán Mullan · Journal of Mathematical Cryptology · 2011
Abstract Stickel's key agreement scheme was successfully cryptanalysed by V. Shpilrain when GL( n, q ) is used as a platform. Shpilrain suggested the algebra of all (not necessarily invertible) n × n matrices defined over some finite ring R would make a more secure platform. He also suggested a more general method of generating keys, involving polynomials of matrices over R . When R = 𝔽 q , we show that these variants of Stickel's scheme are susceptible to a linear algebra attack. We discuss other natural candidates for R , and conclude that until a suitable ring is proposed, the variant schemes may be considered insecure.