• VeriSign, Inc., http://www.verisign.com/
• 政府Government CA (by 中華電信), http://www.pki.gov.tw/
• 元智大學YESKEY, http://ca.info.yzu.edu.tw/
• 資策會 CA (stop on 5/20), http://www.ca.seed.net.tw/
• 郵匯局 CA, http://ca.prsb.gov.tw/
• 金資中心 CA, http://www.fisc.org.tw/ca.html
• GTE Government Systems Corporation.- CyberTrust, http://www.cybertrust.gte.com/
• Thawte Consulting Inc. http://www.thawte.com/
• Entrust Technologies, http://www.entrust.com/index.htm

• Xcert Software Inc. http://x.509.com/
• VeriSign OnSite, http://www.verisign.com/onsite/index.html
• Entrust Commerce CA, http://www.entrust.com/set/index.htm
• Entrust Web CA, http://www.entrust.com/webca/
• CompuSource Ltd, http://www.compusource.co.za/
• OpenPathCA, http://www.sse.ie/opca.html
• Baltimore Technologies, http://www.baltimore.ie/
• Netscape ‘s Certificate Server, http://home.netscape.com/certificate/v1.0/

• An overview of the World Wide Web Consortium’s Digital Signatures initiative. http://www.w3.org/pub/WWW/Security/Dsig/Overview.html
• Microsoft Authenticode http://www.microsoft.com/security/tech/authcode/authcode.htm

http://www.microsoft.com/intdev/sdk/default.htm

• Object Signing Resources http://devedge.netscape.com/docs/manuals/signedobj/overview.html
• Netscape Object Signing http://devedge.netscape.com/docs/manuals/signedobj/trust/index.htm
• Marimba Channel Signing, http://www.marimba.com

• Nortel's Certificate Management Service API version 1.0

• Intel's Common Data Security Architecture (CDSA)

http://www.intel.com/ial/security/specs.htm

• Microsoft's CryptoAPI version 2 (ZIP file)

http://www.microsoft.com/intdev/security/capi/capiref.zip

• The SESAME V4 Public Key Management API

• SECUDE - Security Development Environment

• General PKI, http://www.xcert.com/~marcnarc/PKI/ - Marc's useful PKI and X509 links

• RSA Data Security, Inc., http://www.rsa.com/set/index.html
• CyberCash, http://www.cybercash.com/
• Maithean, http://www.maithean.com/
• Terisa Systems, http://www.terisa.com/
• VeriFone, http://www.verifone.com

• The SSL protocol, http://search.netscape.com/newsref/std/SSL.html
• SSLeay and SSLapps FAQ, http://www.psy.uq.oz.au/~ftp/Crypto/
• SSLeay Certificate Cookbook, http://www.camb.opengroup.org/~fjh/Papers/cook/ssl_cook.html

• Internet Connection Server, http://www.verisign.com/ibm/index.html
• Internet Information Server, http://digitalid.verisign.com/ss_intro.html

• RSA Data Security, Inc, http://www.rsa.com/
• W3C Security Resources, http://www.w3.org/Security/Overview.html
• Netscape Security Solutions, http://home.netscape.com/assist/security/

• Warwick Ford, Michael S. Baum, Secure Electronic Commerce : Building the Infrastructure for Digital Signatures and Encryption, Prentice Hall, April 1997, ISBN: 0134763424
• Gail L. Grant, Understanding Digital Signatures : Establishing Trust over the Internet and Other Networks, Computing McGraw-Hill, November 1997, ISBN: 0070125546
• Simson Garfinkel, Gene Spafford, Web Security & Commerce (Nutshell Handbook), O'Reilly & Associates,June 1997, ISBN: 1565922697
• Peter Wayner, Digital Cash : Commerce on the Net, Ap Professional, April 1997, ISBN: 0127887725
• Donal O'Mahony, Michael Peirce, Hitesh Tewari, Electronic Payment Systems (Artech House Computer Science Library), Artech House, June 1997, ISBN: 0890069255