Public-Key Cryptosystems Based on Class Semigroups of Imaginary Quadratic Non-maximal Orders

摘要

In this paper we propose a key-exchange system and a public-key encryption scheme based on the class semigroups of imaginary quadratic non-maximal orders, the former is analogous to the Diffie-Hellman's key-exchange system and the latter is similar to the ElGamal's encryption scheme, whose security is based on the difficulty of the discrete logarithm problem of that class semigroup.