Method for generating authenticated secret codes

摘要

In a method for generating authenticated secret codes the same mathematical computation operations are used in a pre-authentication and a subsequent code construction. For the pre-authentication of the party A and B, each party chooses a finite field GF(p) (GF(q), respectively), an element alpha (ss, respectively) from the finite field GF(p) (GF(q), respectively) and a first secret random number <IMAGE> Then he generates an authentication code <IMAGE> by raising his element alpha (ss, respectively) to the power of his first secret random number <IMAGE> and discloses this together with the finite field GF(p) (GF(q), respectively) and the element alpha (ss, respectively) in authenticated manner. During the code construction, both parties A and B proceed so that each of the two parties A (B, respectively) generates a second secret random number [x epsilon 0 .. q-2] ([y epsilon 0 .. p-2], respectively) and a working code ss<x> ( alpha <y>, respectively), by raising the element ss ( alpha , respectively) of the other party B (A, respectively) to the power of his second secret random number x (y, respectively), and the two parties A and B exchange the values ss<x> and alpha <y> and then calculate the common authenticated secret code <IMAGE> <IMAGE>