| 2385 | Protection of BGP Sessions via the TCP MD5 Signature OptionA. Heffernan · obsoleted by RFC 5925 | Proposed Standard | August 1998 |
| 2890 | Key and Sequence Number Extensions to GREG. Dommety | Proposed Standard | September 2000 |
| 3711 | The Secure Real-time Transport Protocol (SRTP)M. Baugher, D. McGrew, M. Naslund, E. Carrara, K. Norrman | Proposed Standard | March 2004 |
| 3748 | Extensible Authentication Protocol (EAP)B. Aboba, L. Blunk, J. Vollbrecht, J. Carlson, H. Levkowetz, Ed. | Proposed Standard | June 2004 |
| 4253 | The Secure Shell (SSH) Transport Layer ProtocolT. Ylonen, C. Lonvick, Ed. | Proposed Standard | January 2006 |
| 4302 | IP Authentication HeaderS. Kent | Proposed Standard | December 2005 |
| 4303 | IP Encapsulating Security Payload (ESP)S. Kent | Proposed Standard | December 2005 |
| 4555 | IKEv2 Mobility and Multihoming Protocol (MOBIKE)P. Eronen | Proposed Standard | June 2006 |
| 4571 | Framing Real-time Transport Protocol (RTP) and RTP Control Protocol (RTCP) Packets over Connection-Oriented TransportJ. Lazzaro | Proposed Standard | July 2006 |
| 5246 | The Transport Layer Security (TLS) Protocol Version 1.2T. Dierks, E. Rescorla · obsoleted by RFC 8446, RFC 9846 | Proposed Standard | August 2008 |
| 5641 | Layer 2 Tunneling Protocol Version 3 (L2TPv3) Extended Circuit Status ValuesN. McGill, C. Pignataro | Proposed Standard | August 2009 |
| 5764 | Datagram Transport Layer Security (DTLS) Extension to Establish Keys for the Secure Real-time Transport Protocol (SRTP)D. McGrew, E. Rescorla | Proposed Standard | May 2010 |
| 5925 | The TCP Authentication OptionJ. Touch, A. Mankin, R. Bonica | Proposed Standard | June 2010 |
| 6189 | ZRTP: Media Path Key Agreement for Unicast Secure RTPP. Zimmermann, A. Johnston, Ed., J. Callas | Informational | April 2011 |
| 6347 | Datagram Transport Layer Security Version 1.2E. Rescorla, N. Modadugu · obsoleted by RFC 9147 | Proposed Standard | January 2012 |
| 7296 | Internet Key Exchange Protocol Version 2 (IKEv2)C. Kaufman, P. Hoffman, Y. Nir, P. Eronen, T. Kivinen | Internet Standard | October 2014 |
| 7301 | Transport Layer Security (TLS) Application-Layer Protocol Negotiation ExtensionS. Friedl, A. Popov, A. Langley, E. Stephan | Proposed Standard | July 2014 |
| 7841 | RFC Streams, Headers, and BoilerplatesJ. Halpern, Ed., L. Daigle, Ed., O. Kolkman, Ed. | Informational | May 2016 |
| 7850 | Registering Values of the SDP 'proto' Field for Transporting RTP Media over TCP under Various RTP ProfilesS. Nandakumar | Proposed Standard | April 2016 |
| 8095 | Services Provided by IETF Transport Protocols and Congestion Control MechanismsG. Fairhurst, Ed., B. Trammell, Ed., M. Kuehlewind, Ed. | Informational | March 2017 |
| 8229 | TCP Encapsulation of IKE and IPsec PacketsT. Pauly, S. Touati, R. Mantha · obsoleted by RFC 9329 | Proposed Standard | August 2017 |
| 8446 | The Transport Layer Security (TLS) Protocol Version 1.3E. Rescorla · obsoleted by RFC 9846 | Proposed Standard | August 2018 |
| 8547 | TCP-ENO: Encryption Negotiation OptionA. Bittau, D. Giffin, M. Handley, D. Mazieres, E. Smith | Experimental | May 2019 |
| 8548 | Cryptographic Protection of TCP Streams (tcpcrypt)A. Bittau, D. Giffin, M. Handley, D. Mazieres, Q. Slack, E. Smith | Experimental | May 2019 |