An improved digital signature on generalized conic curve over Z_n

In order to overcome the flaw in the Xiao scheme on conic curve over Z_n, of which the published parameter N_n could make the modulus n be factorized, an improved scheme was proposed. In the present scheme, the parameter N_n was kept secretly, and the verifying algorithm was presented. Moreover, generalized conic curve was chosen to replace conic curve. The security analysis showed that the improved scheme is easy to accomplish the convenient embedding plaintext, computing element order and points in the generalized conic curve. In addition, this scheme is a digital signature scheme based on computing discrete logarithm and factorizing great integer, and has more curves for choice than it on conic curve.