1. WAPForum, Wireless Application Protocol: Public Key Infrastructure Definition (W-PKI), 2001. URL http://www.openmobilealliance.org.
2. ITU-T, Recommendation X.509: Information Technology—Open Systems Interconnection—The Directory: Authentication Framework, International Telecommunication Union-Telecommunication Standardization Sector (ITUT), 1997.
3. Internet X.509 Public Key Infrastructure Certificate and CRL Profile (RFC2459), IETF;Housley,1999
4. X.509 Internet Public Key Infrastructure, Online Certificate Status Protocol—OCSP (RFC2560), IETF;Myers,1999
5. VeriSign, Microsoft, webMethods, XML Key Management Specification (Draft Version), VeriSign, April 2001.