Signature schemes based on factoring and discrete logarithms

The paper proposes two new digital signature schemes, the security of which is based on the difficulties of computing discrete logarithms and factoring, the performance of which is similar to those of the original ElGamal signature scheme and the Harn signature scheme. The paper also considers some possible attacks, and shows that the two schemes are more secure than the original ElGamal signature scheme and the Harn signature scheme