| 2104 | HMAC: Keyed-Hashing for Message AuthenticationH. Krawczyk, M. Bellare, R. Canetti | Informational | February 1997 |
| 2202 | Test Cases for HMAC-MD5 and HMAC-SHA-1P. Cheng, R. Glenn | Informational | September 1997 |
| 2247 | Using Domains in LDAP/X.500 Distinguished NamesS. Kille, M. Wahl, A. Grimstad, R. Huber, S. Sataluri | Proposed Standard | January 1998 |
| 2482 | Language Tagging in Unicode Plain TextK. Whistler, G. Adams · obsoleted by RFC 6082 | Historic | 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 |
| 2797 | Certificate Management Messages over CMSM. Myers, X. Liu, J. Schaad, J. Weinstein · obsoleted by RFC 5272 | Proposed Standard | April 2000 |
| 2986 | PKCS #10: Certification Request Syntax Specification Version 1.7M. Nystrom, B. Kaliski | Informational | November 2000 |
| 3066 | Tags for the Identification of LanguagesH. Alvestrand · obsoleted by RFC 4646, RFC 4647 | Best Current Practice | January 2001 |
| 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 |
| 3281 | An Internet Attribute Certificate Profile for AuthorizationS. Farrell, R. Housley · obsoleted by RFC 5755 | Proposed Standard | May 2002 |
| 3629 | UTF-8, a transformation format of ISO 10646F. Yergeau | Internet Standard | November 2003 |
| 3851 | Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 3.1 Message SpecificationB. Ramsdell, Ed. · obsoleted by RFC 5751 | Proposed Standard | July 2004 |
| 3852 | Cryptographic Message Syntax (CMS)R. Housley · obsoleted by RFC 5652 | Proposed Standard | July 2004 |
| 4055 | Additional Algorithms and Identifiers for RSA Cryptography for use in the Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) ProfileJ. Schaad, B. Kaliski, R. Housley | Proposed Standard | June 2005 |
| 4210 | Internet X.509 Public Key Infrastructure Certificate Management Protocol (CMP)C. Adams, S. Farrell, T. Kause, T. Mononen · obsoleted by RFC 9810 | Proposed Standard | September 2005 |
| 4211 | Internet X.509 Public Key Infrastructure Certificate Request Message Format (CRMF)J. Schaad | Proposed Standard | September 2005 |
| 4262 | X.509 Certificate Extension for Secure/Multipurpose Internet Mail Extensions (S/MIME) CapabilitiesS. Santesson | Proposed Standard | December 2005 |
| 5055 | Server-Based Certificate Validation Protocol (SCVP)T. Freeman, R. Housley, A. Malpani, D. Cooper, W. Polk | Proposed Standard | December 2007 |
| 5272 | Certificate Management over CMS (CMC)J. Schaad, M. Myers · obsoleted by RFC 10002 | Proposed Standard | June 2008 |
| 5280 | Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) ProfileD. Cooper, S. Santesson, S. Farrell, S. Boeyen, R. Housley, W. Polk | Proposed Standard | May 2008 |
| 5480 | Elliptic Curve Cryptography Subject Public Key InformationS. Turner, D. Brown, K. Yiu, R. Housley, T. Polk | Proposed Standard | March 2009 |
| 5741 | RFC Streams, Headers, and BoilerplatesL. Daigle, Ed., O. Kolkman, Ed., IAB · obsoleted by RFC 7841 | Informational | December 2009 |
| 5755 | An Internet Attribute Certificate Profile for AuthorizationS. Farrell, R. Housley, S. Turner | Proposed Standard | January 2010 |
| 5911 | New ASN.1 Modules for Cryptographic Message Syntax (CMS) and S/MIMEP. Hoffman, J. Schaad | Informational | June 2010 |