| 8018 | PKCS #5: Password-Based Cryptography Specification Version 2.1K. Moriarty, Ed., B. Kaliski, A. Rusch | Informational | January 2017 |
| 4880 | OpenPGP Message FormatJ. Callas, L. Donnerhacke, H. Finney, D. Shaw, R. Thayer · obsoleted by RFC 9580 | Proposed Standard | November 2007 |
| 4450 | Getting Rid of the Cruft: Report from an Experiment in Identifying and Reclassifying Obsolete Standards DocumentsE. Lear, H. Alvestrand | Informational | March 2006 |
| 4086 | Randomness Requirements for SecurityD. Eastlake 3rd, J. Schiller, S. Crocker | Best Current Practice | June 2005 |
| 3792 | Survey of IPv4 Addresses in Currently Deployed IETF Security Area Standards Track and Experimental DocumentsP. Nesser, II, A. Bergstrom, Ed. | Informational | June 2004 |
| 3651 | Handle System Namespace and Service DefinitionS. Sun, S. Reilly, L. Lannom | Informational | November 2003 |
| 3550 | RTP: A Transport Protocol for Real-Time ApplicationsH. Schulzrinne, S. Casner, R. Frederick, V. Jacobson | Internet Standard | July 2003 |
| 3280 | Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) ProfileR. Housley, W. Polk, W. Ford, D. Solo · obsoleted by RFC 5280 | Proposed Standard | May 2002 |
| 3279 | Algorithms and Identifiers for the Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) ProfileL. Bassham, W. Polk, R. Housley | Proposed Standard | May 2002 |
| 3259 | A Message Bus for Local CoordinationJ. Ott, C. Perkins, D. Kutscher | Informational | May 2002 |
| 2898 | PKCS #5: Password-Based Cryptography Specification Version 2.0B. Kaliski · obsoleted by RFC 8018 | Informational | September 2000 |
| 2459 | Internet X.509 Public Key Infrastructure Certificate and CRL ProfileR. Housley, W. Ford, W. Polk, D. Solo · obsoleted by RFC 3280 | Proposed Standard | January 1999 |
| 2440 | OpenPGP Message FormatJ. Callas, L. Donnerhacke, H. Finney, R. Thayer · obsoleted by RFC 4880 | Proposed Standard | November 1998 |
| 2316 | Report of the IAB Security Architecture WorkshopS. Bellovin | Informational | April 1998 |
| 2315 | PKCS #7: Cryptographic Message Syntax Version 1.5B. Kaliski | Informational | March 1998 |
| 2313 | PKCS #1: RSA Encryption Version 1.5B. Kaliski · obsoleted by RFC 2437 | Informational | March 1998 |
| 2165 | Service Location ProtocolJ. Veizades, E. Guttman, C. Perkins, S. Kaplan | Proposed Standard | June 1997 |
| 2049 | Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and ExamplesN. Freed, N. Borenstein | Draft Standard | November 1996 |
| 2046 | Multipurpose Internet Mail Extensions (MIME) Part Two: Media TypesN. Freed, N. Borenstein | Draft Standard | November 1996 |
| 2025 | The Simple Public-Key GSS-API Mechanism (SPKM)C. Adams | Proposed Standard | October 1996 |
| 1991 | PGP Message Exchange FormatsD. Atkins, W. Stallings, P. Zimmermann · obsoleted by RFC 4880 | Informational | August 1996 |
| 1890 | RTP Profile for Audio and Video Conferences with Minimal ControlAudio-Video Transport Working Group, H. Schulzrinne · obsoleted by RFC 3551 | Proposed Standard | January 1996 |
| 1889 | RTP: A Transport Protocol for Real-Time ApplicationsAudio-Video Transport Working Group, H. Schulzrinne, S. Casner, R. Frederick, V. Jacobson · obsoleted by RFC 3550 | Proposed Standard | January 1996 |
| 1875 | UNINETT PCA Policy StatementsN. Berge | Informational | December 1995 |
| 1848 | MIME Object Security ServicesS. Crocker, N. Freed, J. Galvin, S. Murphy | Historic | October 1995 |
| 1750 | Randomness Recommendations for SecurityD. Eastlake 3rd, S. Crocker, J. Schiller · obsoleted by RFC 4086 | Informational | December 1994 |
| 1704 | On Internet AuthenticationN. Haller, R. Atkinson | Informational | October 1994 |
| 1700 | Assigned NumbersJ. Reynolds, J. Postel · obsoleted by RFC 3232 | Historic | October 1994 |
| 1616 | X.400(1988) for the Academic and Research Community in EuropeRARE WG-MSG Task Force 88, E. Huizer, Ed., J. Romaguera, Ed. | Informational | May 1994 |
| 1505 | Encoding Header Field for Internet MessagesA. Costanzo, D. Robinson, R. Ullmann | Experimental | August 1993 |
| 1424 | Privacy Enhancement for Internet Electronic Mail: Part IV: Key Certification and Related ServicesB. Kaliski | Historic | February 1993 |
| 1422 | Privacy Enhancement for Internet Electronic Mail: Part II: Certificate-Based Key ManagementS. Kent | Historic | February 1993 |
| 1421 | Privacy Enhancement for Internet Electronic Mail: Part I: Message Encryption and Authentication ProceduresJ. Linn | Historic | February 1993 |