[June 30, 2000] Digital Signatures for the v1.0 Internet Open Trading Protocol (IOTP). "This document covers how digital signatures may be used with XML documents to provide authentication and tamper-proof protocol messages specifically for Version 1.0 of the IOTP protocol. The reader should recognize that an effort towards general XML digital signatures exists but is unlikely to produce its final result in time for IOTP Version 1.0. Future versions of IOTP will probably adopt by reference the results of this general XML digital signature effort. . . The Internet Open Trading Protocol (IOTP) provides a payment system independent interoperable framework for Internet commerce as documented in [RFC 2801]. All IOTP messages are XML documents. XML, the Extensible Markup Language [XML], is a syntactical standard promulgated by the World Wide Web Consortium. XML is intended primarily for structuring data exchanged and served over the World Wide Web. Although IOTP assumes that any payment system used with it provides its own security, there are numerous cases where IOTP requires authentication and integrity services for portions of the XML messages it specifies."
Digital Signatures for the v1.0 Internet Open Trading Protocol (IOTP). Network Working Group, RFC 2802. [cache]