关键词: 复合服务, 移动Agent, 数字签名, 圆锥曲线

Abstract: In order to prevent the signing key from being compromised via network transformation and being compromised on malicious hosts while compositing services using mobile agents，this paper proposes an secure signature scheme using conic curves.In this scheme，mobile agents need not to carry the private key when they generate digital signatures on behalf of the original service.The security of this scheme relies on the difficulty in solving discrete logarithm problems on conic curves and the difficulty of integer factorization.

Key words: services composition, mobile agent, digital signature, conic curve