A Diffie-Hellman Key Exchange Using Matrices Over Non Commutative Rings
  We consider a key exchange procedure whose security is based on the difficulty of computing discrete logarithms in a group, and where exponentiation is hidden by a conjugation. We give a platform-dependent cryptanalysis of this protocol. Finally, to take full advantage of this procedure, we propose a group of matrices over a noncommutative ring as platform group 
Mohammad Eftekhari (LAMFA)
cs.CR