| 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 |
| 1750 | Randomness Recommendations for SecurityD. Eastlake 3rd, S. Crocker, J. Schiller · obsoleted by RFC 4086 | Informational | December 1994 |
| 1847 | Security Multiparts for MIME: Multipart/Signed and Multipart/EncryptedJ. Galvin, S. Murphy, S. Crocker, N. Freed | Proposed Standard | October 1995 |
| 2104 | HMAC: Keyed-Hashing for Message AuthenticationH. Krawczyk, M. Bellare, R. Canetti | Informational | February 1997 |
| 2222 | Simple Authentication and Security Layer (SASL)J. Myers · obsoleted by RFC 4422, RFC 4752 | Proposed Standard | October 1997 |
| 2246 | The TLS Protocol Version 1.0T. Dierks, C. Allen · obsoleted by RFC 4346 | Historic | January 1999 |
| 2289 | A One-Time Password SystemN. Haller, C. Metz, P. Nesser, M. Straw | Internet Standard | February 1998 |
| 2316 | Report of the IAB Security Architecture WorkshopS. Bellovin | Informational | April 1998 |
| 2385 | Protection of BGP Sessions via the TCP MD5 Signature OptionA. Heffernan · obsoleted by RFC 5925 | Proposed Standard | August 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 |
| 2407 | The Internet IP Security Domain of Interpretation for ISAKMPD. Piper · obsoleted by RFC 4306 | Historic | November 1998 |
| 2411 | IP Security Document RoadmapR. Thayer, N. Doraswamy, R. Glenn · obsoleted by RFC 6071 | Informational | November 1998 |
| 2535 | Domain Name System Security ExtensionsD. Eastlake 3rd · obsoleted by RFC 4033, RFC 4034, RFC 4035 | Proposed Standard | March 1999 |
| 2744 | Generic Security Service API Version 2 : C-bindingsJ. Wray | Proposed Standard | January 2000 |
| 2993 | Architectural Implications of NATT. Hain | Informational | November 2000 |
| 3174 | US Secure Hash Algorithm 1 (SHA1)D. Eastlake 3rd, P. Jones | Informational | September 2001 |
| 3261 | SIP: Session Initiation ProtocolJ. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, E. Schooler | Proposed Standard | July 2002 |
| 3445 | Limiting the Scope of the KEY Resource Record (RR)D. Massey, S. Rose · obsoleted by RFC 4033, RFC 4034, RFC 4035 | Proposed Standard | December 2002 |