In this paper we present a key exchange protocol based on multivariate non-commutative polynomial rings, analogous to the classic Diffie-Hellman method. Ourtechnique extends the proposed scheme of Boucher et al. from 2010. Their method was broken by Dubois and Kammerer in 2011, who exploited the Euclidean domain structure of the chosen ring. However, our proposal is immune against such attacks, without losing the advantages of non-commutative polynomial rings as outlined by Boucher et al. Moreover, our extension is not restricted to any particular ring, but is designed to allow users to readily choose from a large class of rings when applying the protocol.
more here...............http://arxiv.org/pdf/1407.1270v1.pdf
more here...............http://arxiv.org/pdf/1407.1270v1.pdf