A Probabilistic Public Key Cryptosystem with a Message Expansion of 1
一个数据膨胀率为1的概率公钥密码系统

Based on the RSA public key cryptosystem, a probabilistic public key cryptosystem is proposed, using the techniques of time stamp and hash function. The new scheme makes use of the intractability of solving the square roots in quadratic congruence equation with a Blum integer modulus, whose cipher intensity is no lower than that of RSA scheme and of the difficulty of solving the square root in quadratic congruence equation. In our scheme encoding and decoding requires O(k3) operation, where k is the length of modulus. And the message expansion is 1, so the scheme is optimal in the message expansion.