Abstract: This paper firstly analysed the typical application of the XML multi-party communication chain business in the current Web server architecture and built up the corresponding research model. Based on the modcl,this paper proposed a new encryption technology named untied signature, which can solve the problems of the reduplicate signature and not strict information association using the traditional signature technology. This paper also analysed the limitations of using current XMI. specification to fulfill the encryption technology, and then raised the implementation scheme of XML untied signature. Finally, this paper presented the syntax definition of XML united signature.

Key words: Chain business of XML multi-party communication, United signature, XML signature, XML united signature