关键词: Web服务, 会话认证, 公钥生成器（PKG）, 聚合签名

Abstract: In order to satisfy the session authentication requirement?of Web services, and to enhance the authentication efficiency in multi-service transaction environment, an algorithm of identity-based aggregate signature is proposed based on the idea of signature scheme without trusted PKG in IBC system. Meantime, a new service session authentication protocol ABSAP（Aggregate signature-Based Session Authentication Protocol）is designed using the algorithm. The protocol can not only assure instances in multi-service transaction environment of secure session share, but also resolve the problems of key escrow and signature anti-forging by PKG. Authenticators can assure all signatures properly processed by verifying the aggregate signature ciphered from authentication information of all session instances. In this way, messages sending for session authentication are reduced. Compared to similar schema, the protocol has higher calculation efficiency.

Key words: Web service, session authentication, Public Key Generator（PKG）, aggregate signature