Abstract: The digital signature algorithm proposed by SHEN Qun et al．gives analytical attack,which is based on elliptic curve and factoring problems．If the difficulties of elliptic curve or factoring can be solved,SHEN Qun digital signature schemes can be attacked．A new digital signature algorithm was proposed,which is based on elliptic curve and factoring problems．The correctness,security and unforgeability were proved．Another,a new digital signature algorithm with message recovery was proposed,which is based on elliptic curve and factoring problems．The correctness,security and unforgeability were proved.

Key words: Elliptic curve,Factoring,Digital signature,Message recovery,Forgery attack