| 1994 | PPP Challenge Handshake Authentication Protocol (CHAP)W. Simpson | Draft Standard | August 1996 |
| 2069 | An Extension to HTTP : Digest Access AuthenticationJ. Franks, P. Hallam-Baker, J. Hostetler, P. Leach, A. Luotonen, E. Sink, L. Stewart · obsoleted by RFC 2617 | Proposed Standard | January 1997 |
| 2119 | Key words for use in RFCs to Indicate Requirement LevelsS. Bradner | Best Current Practice | March 1997 |
| 2617 | HTTP Authentication: Basic and Digest Access AuthenticationJ. Franks, P. Hallam-Baker, J. Hostetler, S. Lawrence, P. Leach, A. Luotonen, L. Stewart · obsoleted by RFC 7235, RFC 7615, RFC 7616, RFC 7617 | Draft Standard | June 1999 |
| 2865 | Remote Authentication Dial In User Service (RADIUS)C. Rigney, S. Willens, A. Rubens, W. Simpson | Draft Standard | June 2000 |
| 3261 | SIP: Session Initiation ProtocolJ. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, E. Schooler | Proposed Standard | July 2002 |
| 3310 | Hypertext Transfer Protocol (HTTP) Digest Authentication Using Authentication and Key Agreement (AKA)A. Niemi, J. Arkko, V. Torvinen | Informational | September 2002 |
| 3579 | RADIUS (Remote Authentication Dial In User Service) Support For Extensible Authentication Protocol (EAP)B. Aboba, P. Calhoun | Informational | September 2003 |
| 3588 | Diameter Base ProtocolP. Calhoun, J. Loughney, E. Guttman, G. Zorn, J. Arkko · obsoleted by RFC 6733 | Proposed Standard | September 2003 |
| 3851 | Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 3.1 Message SpecificationB. Ramsdell, Ed. · obsoleted by RFC 5751 | Proposed Standard | July 2004 |
| 3966 | The tel URI for Telephone NumbersH. Schulzrinne | Proposed Standard | December 2004 |
| 4346 | The Transport Layer Security (TLS) Protocol Version 1.1T. Dierks, E. Rescorla · obsoleted by RFC 5246 | Historic | April 2006 |
| 4590 | RADIUS Extension for Digest AuthenticationB. Sterman, D. Sadolevsky, D. Schwartz, D. Williams, W. Beck · obsoleted by RFC 5090 | Proposed Standard | July 2006 |
| 4740 | Diameter Session Initiation Protocol (SIP) ApplicationM. Garcia-Martin, Ed., M. Belinchon, M. Pallares-Lopez, C. Canales-Valenzuela, K. Tammi | Proposed Standard | November 2006 |