• CHO SOOJIN (Department of Mathematics Ajou University) ;
  • HA KIL-CHAN (Department of Applied Mathematics Sejong University) ;
  • KIM YOUNG-ONE (Department of Mathematics Seoul National University) ;
  • MOON DONGHO (Department of Applied Mathematics Sejong University)
  • Published : 2005.11.01


A key exchange protocol using commutative subalge-bras of a full matrix algebra is considered. The security of the protocol depends on the difficulty of solving matrix equations XRY = T, with given matrices R and T. We give a polynomial time algorithm to solve XRY = T for the choice of certain types of subalgebras. We also compare the efficiency of the protocol with the Diffie-Hellman key exchange protocol on the key computation time and the key size.


key exchange protocol;matrix algebra;Diffie-Hellman key exchange


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