Abstract: In order to solve the problem of strong forward security in digital signature schemes, a class of forward security digital signature scheme based on elliptic curve is analyzed. It is proved that the scheme does not satisfy the backward security. An elliptic curve digital signature scheme with strong forward security is proposed by introducing the double private key evolution method. After security analysis, the improved scheme has strong forward security and anti-forgery. It is also a backward-secure digital signature scheme.

Key words: strong forward security, elliptic curve, key evolution, digital signature