| 1321 | The MD5 Message-Digest AlgorithmR. Rivest | Informational | April 1992 |
| 1510 | The Kerberos Network Authentication Service (V5)J. Kohl, C. Neuman · obsoleted by RFC 4120, RFC 6649 | Historic | September 1993 |
| 2104 | HMAC: Keyed-Hashing for Message AuthenticationH. Krawczyk, M. Bellare, R. Canetti | Informational | February 1997 |
| 2205 | Resource ReSerVation Protocol (RSVP) -- Version 1 Functional SpecificationR. Braden, Ed., L. Zhang, S. Berson, S. Herzog, S. Jamin | Proposed Standard | September 1997 |
| 2207 | RSVP Extensions for IPSEC Data FlowsL. Berger, T. O'Malley | Proposed Standard | September 1997 |
| 2315 | PKCS #7: Cryptographic Message Syntax Version 1.5B. Kaliski | Informational | March 1998 |
| 2401 | Security Architecture for the Internet ProtocolS. Kent, R. Atkinson · obsoleted by RFC 4301 | Proposed Standard | November 1998 |
| 2402 | IP Authentication HeaderS. Kent, R. Atkinson · obsoleted by RFC 4302, RFC 4305 | Proposed Standard | November 1998 |
| 2406 | IP Encapsulating Security Payload (ESP)S. Kent, R. Atkinson · obsoleted by RFC 4303, RFC 4305 | Proposed Standard | November 1998 |
| 2409 | The Internet Key Exchange (IKE)D. Harkins, D. Carrel · obsoleted by RFC 4306 | Historic | November 1998 |
| 2440 | OpenPGP Message FormatJ. Callas, L. Donnerhacke, H. Finney, R. Thayer · obsoleted by RFC 4880 | Proposed Standard | November 1998 |
| 2495 | Definitions of Managed Objects for the DS1, E1, DS2 and E2 Interface TypesD. Fowler, Ed. · obsoleted by RFC 3895 | Proposed Standard | January 1999 |
| 2560 | X.509 Internet Public Key Infrastructure Online Certificate Status Protocol - OCSPM. Myers, R. Ankney, A. Malpani, S. Galperin, C. Adams · obsoleted by RFC 6960 | Proposed Standard | June 1999 |
| 2746 | RSVP Operation Over IP TunnelsA. Terzis, J. Krawczyk, J. Wroclawski, L. Zhang | Proposed Standard | January 2000 |
| 2747 | RSVP Cryptographic AuthenticationF. Baker, B. Lindell, M. Talwar | Proposed Standard | January 2000 |
| 2749 | COPS usage for RSVPS. Herzog, Ed., J. Boyle, R. Cohen, D. Durham, R. Rajan, A. Sastry | Proposed Standard | January 2000 |
| 2750 | RSVP Extensions for Policy ControlS. Herzog | Proposed Standard | January 2000 |
| 2865 | Remote Authentication Dial In User Service (RADIUS)C. Rigney, S. Willens, A. Rubens, W. Simpson | Draft Standard | June 2000 |
| 3182 | Identity Representation for RSVPS. Yadav, R. Yavatkar, R. Pabbati, P. Ford, T. Moore, S. Herzog, R. Hess | Proposed Standard | October 2001 |
| 3369 | Cryptographic Message Syntax (CMS)R. Housley · obsoleted by RFC 3852 | Proposed Standard | September 2002 |
| 3588 | Diameter Base ProtocolP. Calhoun, J. Loughney, E. Guttman, G. Zorn, J. Arkko · obsoleted by RFC 6733 | Proposed Standard | September 2003 |
| 3961 | Encryption and Checksum Specifications for Kerberos 5K. Raeburn | Proposed Standard | February 2005 |