<?xml version='1.0'encoding='utf-8'?>encoding='UTF-8'?> <!DOCTYPE rfc [ <!ENTITY nbsp " "> <!ENTITY zwsp "​"> <!ENTITY nbhy "‑"> <!ENTITY wj "⁠"> ]><?xml-stylesheet type="text/xsl" href="rfc2629.xslt" ?> <!-- generated by https://github.com/cabo/kramdown-rfc version 1.7.27 (Ruby 3.3.6) --><rfc xmlns:xi="http://www.w3.org/2001/XInclude" ipr="trust200902" docName="draft-ietf-uta-require-tls13-12" number="9852" category="bcp" consensus="true" submissionType="IETF" updates="9325" obsoletes="" tocInclude="true" sortRefs="true" symRefs="true"version="3"> <!-- xml2rfc v2v3 conversion 3.28.1 -->version="3" xml:lang="en"> <front> <titleabbrev="require-tls1.3">Newabbrev="New Protocols Using TLS Must Require TLS 1.3">New Protocols Using TLS Must Require TLS 1.3</title> <seriesInfoname="Internet-Draft" value="draft-ietf-uta-require-tls13-12"/>name="RFC" value="9852"/> <seriesInfo name="BCP" value="195"/> <author fullname="Rich Salz"> <organization>Akamai Technologies</organization> <address> <email>rsalz@akamai.com</email> </address> </author> <author fullname="Nimrod Aviram"> <organization/> <address> <email>nimrod.aviram@gmail.com</email> </address> </author> <dateyear="2025" month="April" day="14"/>year="2026" month="January"/> <area>Security</area> <workgroup>Using TLS in Applications</workgroup> <keyword>TLS</keyword> <keyword>TLS Transition</keyword> <keyword>TLS Support</keyword> <keyword>Interoperability</keyword> <keyword>features</keyword> <abstract><?line 123?><t>TLS 1.3useiswidespread, itwidely used, has had comprehensive security proofs, anditimproves both security and privacyoverdeficiencies in TLS 1.2. Therefore, new protocols that use TLS must require TLS 1.3. As DTLS 1.3 is not widely available or deployed, this prescription does not pertain to DTLS (in any DTLS version); it pertains to TLS only.</t> <t>This document updatesRFC9325 andRFC 9325. It discusses post-quantum cryptography and the security and privacy improvementsoverin TLS1.21.3 asathe rationale forthatthe update.</t> </abstract><note removeInRFC="true"> <name>About This Document</name> <t> Status information for this document may be found at <eref target="https://datatracker.ietf.org/doc/draft-ietf-uta-require-tls13/"/>. </t> <t> Discussion of this document takes place on the Using TLS in Applications Working Group mailing list (<eref target="mailto:uta@ietf.org"/>), which is archived at <eref target="https://mailarchive.ietf.org/arch/browse/uta/"/>. Subscribe at <eref target="https://www.ietf.org/mailman/listinfo/uta/"/>. </t> <t>Source for this draft and an issue tracker can be found at <eref target="https://github.com/richsalz/draft-use-tls13"/>.</t> </note></front> <middle><?line 134?><section anchor="sec-reasons"> <name>Introduction</name> <t>This document specifiesthat, since TLS 1.3 use is widespread,that new protocols that use TLS mustrequire andassume that TLS 1.3 is available and require itsexistence. It updates <xref target="RFC9325"/> as described in <xref target="rfc9325-updates"/>.use. As DTLS 1.3 is not widely available or deployed, this prescription does not pertain to DTLS (in any DTLS version); it pertains to TLS only.</t> <t>TLS 1.3 <xreftarget="TLS13"/>target="RFC9846"/> is in widespread use and fixes most known deficiencies with TLS 1.2. Examples of this include encrypting more of the traffic so that it is not readable by outsiders and removing most cryptographic primitives now considered weak. Importantly, the protocol has had comprehensive security proofs and should provide excellent security without any additional configuration.</t> <t>TLS 1.2 <xreftarget="TLS12"/>target="RFC5246"/> is in use and can be configured such that it provides good security properties. However, TLS 1.2 suffers from several deficiencies, as described in <xref target="sec-considerations"/>. Addressing them usually requires bespoke configuration.</t> <t>This document updatesRFC9325 and<xref target="RFC9325"/>. It discusses post-quantum cryptography andfixed weaknessesthe security and privacy improvements in TLS1.21.3 asathe rationale forthat update.</t>the update. See <xref target="rfc9325-updates"/>.</t> </section> <sectionanchor="conventions-and-definitions"> <name>Conventions and Definitions</name> <t>Theanchor="conventions"> <name>Conventions</name> <t> The key words "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>", "<bcp14>MAY</bcp14>", and "<bcp14>OPTIONAL</bcp14>" in this document are to be interpreted as described inBCP 14BCP 14 <xref target="RFC2119"/> <xref target="RFC8174"/> when, and only when, they appear in all capitals, as shownhere.</t> <?line -18?>here. </t> </section> <section anchor="implications-for-post-quantum-cryptography-pqc"> <name>Implications forpost-quantum cryptographyPost-Quantum Cryptography (PQC)</name><t>Cryptographically-relevant quantum computers (CRQC),<t>Cryptographically Relevant Quantum Computers (CRQCs), once available, will have a huge impact on TLS traffic (see, e.g., <xref section="2" sectionFormat="of" target="I-D.ietf-pquip-pqc-engineers"/>). To mitigate this, TLS applications will need to migrate to Post-Quantum Cryptography (PQC) <xref target="PQC"/>. Detailed considerations of when an application requires PQC or when a CRQC is a threat that an applicationneedneeds to protectagainst,against are beyond the scope of this document.</t><t>For TLS it<t>It is important to note that thefocus of these efforts within theTLSWGWorking Group is focusing its efforts on TLS 1.3 orlater, and thatlater; TLS 1.2 will not be supported (see <xreftarget="TLS12FROZEN"/>).target="RFC9851"/>). This is one more reason for new protocols to require TLS to default to TLS 1.3, where PQC is actively being standardized, as this gives new applications the option to use PQC.</t> </section> <section anchor="tls-use-by-other-protocols-and-applications"> <name>TLS Use by Other Protocols and Applications</name> <t>Any new protocol that uses TLS <bcp14>MUST</bcp14> specify TLS 1.3 as itsdefault TLS 1.3.default. For example, QUIC <xreftarget="QUICTLS"/>target="RFC9001"/> requires TLS 1.3 and specifies that endpoints <bcp14>MUST</bcp14> terminate the connection if an older version is used.</t> <t>If deployment considerations are a concern, the protocol <bcp14>MAY</bcp14> specify TLS 1.2 as an additional, non-default option. As a counter example, the Usage Profile for DNS over TLS <xreftarget="DNSTLS"/>target="RFC8310"/> specifies TLS 1.2 as the default, while also allowing TLS 1.3. For newer specifications that choose to support TLS 1.2, those preferences are to be reversed.</t> <t>The initial TLS handshake allows a client to specify which versions oftheTLSprotocolitsupportssupports, and the server is intended to pick the highest version that it also supports. This is known asthe"TLS versionnegotiation," andnegotiation"; protocol and negotiation details are discussed in <xref section="4.2.1"sectionFormat="comma" target="TLS13"/>sectionFormat="of" target="RFC9846"/> and <xref section="E"sectionFormat="comma" target="TLS12"/>.sectionFormat="of" target="RFC5246"/>. Many TLS libraries provide a way for applications to specify the range of versions they want, including an open interval where only the lowest or highest version is specified.</t> <t>If the application is using a TLS implementation that supportsthis,TLS version negotiation and if it knows that the TLS implementation will use the highest version supported, then clients <bcp14>SHOULD</bcp14> specify just the minimum version they want. This <bcp14>MUST</bcp14> be TLS 1.3 or TLS 1.2, depending on the circumstances described in the above paragraphs.</t> </section> <section anchor="rfc9325-updates"> <name>Changes to RFC 9325</name> <t><xref target="RFC9325"/> provides recommendations for ensuring the security of deployed services that use TLS and, unlike this document, DTLS as well.At the time it was published, it described availability of<xref target="RFC9325"/> describes TLS 1.3 as "widelyavailable." The transitionavailable", andadoption mentioned in that documentthe transition to TLS 1.3 hasgrown, and thisfurther increased since publication of that document. This documentnowthus makes two changes to the recommendations in <xref section="3.1.1"sectionFormat="comma"sectionFormat="of" target="RFC9325"/>:</t> <ul spacing="normal"> <li> <t>That section says that TLS 1.3 <bcp14>SHOULD</bcp14> be supported; this document mandates that TLS 1.3 <bcp14>MUST</bcp14> be supported for newTLS-using protocols.</t>protocols using TLS.</t> </li> <li> <t>That section says that TLS 1.2 <bcp14>MUST</bcp14> be supported; this document says that TLS 1.2 <bcp14>MAY</bcp14> be supported as described above.</t> </li> </ul> <t>Again, these changes only apply to TLS, and not DTLS.</t> </section> <section anchor="sec-considerations"> <name>Security Considerations</name> <t>TLS 1.2 was specified with several cryptographic primitives and design choices that have, over time, become significantly weaker. The purpose of this section is to briefly survey several such prominent problems that have affected the protocol. It should be noted, however, that TLS 1.2 can be configured securely; it is merely much more difficult to configure it securely as opposed to using its modern successor, TLS 1.3. See <xref target="RFC9325"/> for a more thorough guide on the secure deployment of TLS 1.2.</t><t>Firstly, the TLS 1.2 protocol,<t>First, without any extensions, TLS 1.2 is vulnerable to renegotiation attacks (see <xref target="RENEG1"/> and <xref target="RENEG2"/>) and the Triple Handshake attack (see <xref target="TRIPLESHAKE"/>). Broadly, these attacks exploit the protocol's support for renegotiation in order to inject a prefix chosen by the attacker into the plaintext stream. This is usually a devastating threat inpractice, thatpractice (e.g., it allowse.g. obtainingan attacker to obtain secret cookies in a websetting.setting). In light of the above problems, <xref target="RFC5746"/> specifies an extension that prevents this category of attacks. To securely deploy TLS 1.2, either renegotiation must be disabled entirely, or this extension must be used. Additionally, clients must not allow servers to renegotiate the certificate during a connection.</t><t>Secondly,<t>Second, the original key exchange methods specified forthe protocol,TLS 1.2, namely RSA key exchange and finite field Diffie-Hellman, suffer from several weaknesses.Similarly, toTo securely deploy the protocol, most of these key exchange methods must be disabled. See <xref target="I-D.ietf-tls-deprecate-obsolete-kex"/> for details.</t><t>Thirdly,<t>Third, symmetric cipherswhich were widely-usedthat are widely used inthe protocol,TLS 1.2, namely RC4 andCBCCipher Block Chaining (CBC) cipher suites, suffer from several weaknesses. RC4 suffers from exploitable biases in its key stream; see <xref target="RFC7465"/>. CBC cipher suites have been a source of vulnerabilities throughout the years. A straightforward implementation of these cipher suites inherently suffers from the Lucky13 timing attack <xref target="LUCKY13"/>. The first attempt to implement the cipher suites in constant time introduced an even more severe vulnerability <xref target="LUCKY13FIX"/>.There have been further similar vulnerabilities throughout the years exploiting CBC cipher suites; refer to, e.g.,Refer to <xref target="CBCSCANNING"/> forananother example of a vulnerability with CBC cipher suites and a survey of similar works.</t> <t>In addition, TLS 1.2 was affected by several other attacks that TLS 1.3 is immune to: BEAST <xref target="BEAST"/>, Logjam <xref target="WEAKDH"/>, FREAK <xref target="FREAK"/>, and SLOTH <xref target="SLOTH"/>.</t><t>And finally,<t>Finally, whileapplication layerapplication-layer traffic in TLS 1.2 is always encrypted, most of the content of the handshake messagesareis not. Therefore, the privacy provided is suboptimal. This is a protocol issue that cannot be addressed by configuration.</t> </section> <section anchor="iana"> <name>IANA Considerations</name> <t>This documentmakeshas norequests to IANA.</t>IANA actions.</t> </section> </middle> <back> <displayreference target="I-D.ietf-tls-deprecate-obsolete-kex" to="KEY-EXCHANGE"/> <displayreference target="I-D.ietf-pquip-pqc-engineers" to="PQC-FOR-ENGINEERS"/> <displayreference target="RFC5246" to="TLS12"/> <displayreference target="RFC9846" to="TLS13"/> <displayreference target="RFC9851" to="TLS12FROZEN"/> <displayreference target="RFC9001" to="QUICTLS"/> <displayreference target="RFC8310" to="DNSTLS"/> <references anchor="sec-combined-references"> <name>References</name> <references anchor="sec-normative-references"> <name>Normative References</name><reference anchor="TLS12"> <front> <title>The Transport Layer Security (TLS) Protocol Version 1.2</title> <author fullname="T. Dierks" initials="T." surname="Dierks"/> <author fullname="E. Rescorla" initials="E." surname="Rescorla"/> <date month="August" year="2008"/> <abstract> <t>This document specifies Version 1.2<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5246.xml"/> <!-- [RFC9846 / TLS13] draft-ietf-tls-rfc8446bis-14 companion doc RFC 9846 AUTH48 state as ofthe Transport Layer Security (TLS) protocol. The TLS protocol provides communications security over the Internet. The protocol allows client/server applications to communicate in a way that is designed to prevent eavesdropping, tampering, or message forgery. [STANDARDS-TRACK]</t> </abstract> </front> <seriesInfo name="RFC" value="5246"/> <seriesInfo name="DOI" value="10.17487/RFC5246"/> </reference>1/5/2026 --> <referenceanchor="TLS13">anchor="RFC9846" target="https://www.rfc-editor.org/info/rfc9846"> <front> <title>The Transport Layer Security (TLS) Protocol Version 1.3</title> <authorfullname="Eric Rescorla"initials="E."surname="Rescorla">surname="Rescorla" fullname="Eric Rescorla"> <organization>Independent</organization> </author> <dateday="17" month="February" year="2025"/> <abstract> <t> This document specifies version 1.3 of the Transport Layer Security (TLS) protocol. TLS allows client/server applications to communicate over the Internet in a way that is designed to prevent eavesdropping, tampering, and message forgery. This document updates RFCs 5705, 6066, 7627, and 8422 and obsoletes RFCs 5077, 5246, 6961, 8422, and 8446. This document also specifies new requirements for TLS 1.2 implementations. </t> </abstract>month='January' year='2026'/> </front> <seriesInfoname="Internet-Draft" value="draft-ietf-tls-rfc8446bis-12"/>name="RFC" value="9846"/> <seriesInfo name="DOI" value="10.17487/RFC9846"/> </reference> <!-- [RFC9851 / TLS12FROZEN] draft-ietf-tls-tls12-frozen-08 AUTH48 state as of 1/5/2026 --> <referenceanchor="TLS12FROZEN">anchor="RFC9851" target="https://www.rfc-editor.org/info/rfc9851"> <front> <title>TLS 1.2 is in Feature Freeze</title> <authorfullname="Rich Salz"initials="R."surname="Salz">surname="Salz" fullname="Rich Salz"> <organization>Akamai Technologies</organization> </author> <authorfullname="Nimrod Aviram"initials="N."surname="Aviram">surname="Aviram" fullname="Nimrod Aviram"> </author> <dateday="3" month="April" year="2025"/> <abstract> <t> Use of TLS 1.3, which fixes some known deficiencies in TLS 1.2, is growing. This document specifies that outside of urgent security fixes (as determine by TLS WG consensus), new TLS Exporter Labels, or new Application-Layer Protocol Negotiation (ALPN) Protocol IDs, no changes will be approved for TLS 1.2. This prescription does not pertain to DTLS (in any DTLS version); it pertains to TLS only. </t> </abstract> </front> <seriesInfo name="Internet-Draft" value="draft-ietf-tls-tls12-frozen-08"/> </reference> <reference anchor="RFC2119"> <front> <title>Key words for use in RFCs to Indicate Requirement Levels</title> <author fullname="S. Bradner" initials="S." surname="Bradner"/> <date month="March" year="1997"/> <abstract> <t>In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.</t> </abstract> </front> <seriesInfo name="BCP" value="14"/> <seriesInfo name="RFC" value="2119"/> <seriesInfo name="DOI" value="10.17487/RFC2119"/> </reference> <reference anchor="RFC8174"> <front> <title>Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words</title> <author fullname="B. Leiba" initials="B." surname="Leiba"/> <date month="May" year="2017"/> <abstract> <t>RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings.</t> </abstract>month="January" year='2026'/> </front> <seriesInfoname="BCP" value="14"/> <seriesInfoname="RFC"value="8174"/>value="9851"/> <seriesInfo name="DOI"value="10.17487/RFC8174"/> </reference> <reference anchor="RFC9325"> <front> <title>Recommendations for Secure Use of Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS)</title> <author fullname="Y. Sheffer" initials="Y." surname="Sheffer"/> <author fullname="P. Saint-Andre" initials="P." surname="Saint-Andre"/> <author fullname="T. Fossati" initials="T." surname="Fossati"/> <date month="November" year="2022"/> <abstract> <t>Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS) are used to protect data exchanged over a wide range of application protocols and can also form the basis for secure transport protocols. Over the years, the industry has witnessed several serious attacks on TLS and DTLS, including attacks on the most commonly used cipher suites and their modes of operation. This document provides the latest recommendations for ensuring the security of deployed services that use TLS and DTLS. These recommendations are applicable to the majority of use cases.</t> <t>RFC 7525, an earlier version of the TLS recommendations, was published when the industry was transitioning to TLS 1.2. Years later, this transition is largely complete, and TLS 1.3 is widely available. This document updates the guidance given the new environment and obsoletes RFC 7525. In addition, this document updates RFCs 5288 and 6066 in view of recent attacks.</t> </abstract> </front> <seriesInfo name="BCP" value="195"/> <seriesInfo name="RFC" value="9325"/> <seriesInfo name="DOI" value="10.17487/RFC9325"/>value="10.17487/RFC9851"/> </reference> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9325.xml"/> </references> <references anchor="sec-informative-references"> <name>Informative References</name><reference anchor="QUICTLS"> <front> <title>Using TLS to Secure QUIC</title> <author fullname="M. Thomson" initials="M." role="editor" surname="Thomson"/> <author fullname="S. Turner" initials="S." role="editor" surname="Turner"/> <date month="May" year="2021"/> <abstract> <t>This document describes how Transport Layer Security (TLS) is used to secure QUIC.</t> </abstract> </front> <seriesInfo name="RFC" value="9001"/> <seriesInfo name="DOI" value="10.17487/RFC9001"/> </reference> <reference anchor="DNSTLS"> <front> <title>Usage Profiles for DNS over TLS and DNS over DTLS</title> <author fullname="S. Dickinson" initials="S." surname="Dickinson"/> <author fullname="D. Gillmor" initials="D." surname="Gillmor"/> <author fullname="T. Reddy" initials="T." surname="Reddy"/> <date month="March" year="2018"/> <abstract> <t>This document discusses usage profiles, based on one or more authentication mechanisms, which can be used for DNS over Transport Layer Security (TLS) or Datagram TLS (DTLS). These profiles can increase the privacy of DNS transactions compared to using only cleartext DNS. This document also specifies new authentication mechanisms -- it describes several ways that a DNS client can use an authentication domain name to authenticate a (D)TLS connection to a DNS server. Additionally, it defines (D)TLS protocol profiles for DNS clients and servers implementing DNS over (D)TLS. This document updates RFC 7858.</t> </abstract> </front> <seriesInfo name="RFC" value="8310"/> <seriesInfo name="DOI" value="10.17487/RFC8310"/> </reference><xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5746.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9001.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8310.xml"/> <reference anchor="PQC" target="https://www.nist.gov/cybersecurity/what-post-quantum-cryptography"> <front> <title>What Is Post-Quantum Cryptography?</title> <author><organization/><organization>NIST</organization> </author> <dateyear="2024" month="August"/>year="2025" month="June"/> </front> </reference> <reference anchor="TRIPLESHAKE"target="https://mitls.org/pages/attacks/3SHAKE">target="https://web.archive.org/web/20250804151857/https://mitls.org/pages/attacks/3SHAKE"> <front> <title>Triple Handshakes ConsideredHarmfulHarmful: Breaking and Fixing Authentication over TLS</title> <author> <organization/> </author><date>n.d.</date></front> <refcontent>Wayback Machine archive</refcontent> </reference> <reference anchor="RENEG1" target="https://web.archive.org/web/20091231034700/http://www.educatedguesswork.org/2009/11/understanding_the_tls_renegoti.html"> <front> <title>Understanding the TLS Renegotiation Attack</title> <author initials="E." surname="Rescorla" fullname="Eric Rescorla"> <organization/> </author><date>n.d.</date> </front><date day="5" month="11" year="2009"/> </front> <refcontent>Wayback Machine archive</refcontent> </reference> <reference anchor="RENEG2" target="https://web.archive.org/web/20091228061844/http://extendedsubset.com/?p=8"> <front> <title>Authentication Gap in TLS Renegotiation</title> <author initials="M." surname="Ray" fullname="Marsh Ray"> <organization/> </author><date>n.d.</date></front> <refcontent>Wayback Machine archive</refcontent> </reference> <reference anchor="LUCKY13" target="http://www.isg.rhul.ac.uk/tls/TLStiming.pdf"> <front> <title>Lucky Thirteen: Breaking the TLS and DTLS record protocols</title> <author initials="N. J." surname="Al Fardan"> <organization/> </author> <author initials="K. G." surname="Paterson"> <organization/> </author><date>n.d.</date><date month="2" year="2013"/> </front> </reference> <reference anchor="LUCKY13FIX" target="https://nds.rub.de/media/nds/veroeffentlichungen/2016/10/19/tls-attacker-ccs16.pdf"> <front> <title>SystematicfuzzingFuzzing andtestingTesting of TLSlibraries</title>Libraries</title> <author initials="J." surname="Somorovsky" fullname="Juraj Somorovsky"> <organization/> </author><date>n.d.</date><date month="10" year="2016"/> </front> <refcontent>CCS '16: Proceedings of the 2016 ACM SIGSAC Conference on Computer and Communications Security, pp. 1492-1504</refcontent> <seriesInfo name="DOI" value="10.1145/2976749.2978411"/> </reference> <reference anchor="CBCSCANNING" target="https://www.usenix.org/system/files/sec19-merget.pdf"> <front> <title>Scalable Scanning and Automatic Classification of TLS Padding Oracle Vulnerabilities</title> <author initials="R." surname="Merget" fullname="Robert Merget"> <organization/> </author> <author initials="J." surname="Somorovsky" fullname="Juraj Somorovsky"> <organization/> </author> <author initials="N." surname="Aviram" fullname="Nimrod Aviram"> <organization/> </author> <author initials="C." surname="Young" fullname="Craig Young"> <organization/> </author> <author initials="J." surname="Fliegenschmidt" fullname="Janis Fliegenschmidt"> <organization/> </author> <author initials="J." surname="Schwenk"fullname="Jörgfullname="Jorg Schwenk"> <organization/> </author> <author initials="Y." surname="Shavitt" fullname="Yuval Shavitt"> <organization/> </author><date>n.d.</date><date month="8" year="2019"/> </front> <refcontent>28th USENIX Security Symposium (USENIX Security 19)</refcontent> </reference> <reference anchor="BEAST" target="http://www.hpcc.ecs.soton.ac.uk/dan/talks/bullrun/Beast.pdf"> <front> <title>HerecomeCome thexor ninjas</title>XOR Ninjas</title> <author initials="T." surname="Duong" fullname="Thai Duong"> <organization/> </author> <author initials="J." surname="Rizzo" fullname="Juliano Rizzo"> <organization/> </author><date>n.d.</date><date month="5" year="2011"/> </front> </reference> <reference anchor="WEAKDH" target="https://dl.acm.org/doi/pdf/10.1145/2810103.2813707"> <front> <title>Imperfectforward secrecy:Forward Secrecy: How Diffie-HellmanfailsFails inpractice</title>Practice</title> <author initials="D." surname="Adrian"> <organization/> </author> <author initials="K." surname="Bhargavan"> <organization/> </author> <author initials="Z." surname="Durumeric"> <organization/> </author> <author initials="P." surname="Gaudry"> <organization/> </author> <author initials="M." surname="Green"> <organization/> </author> <author initials="J. A." surname="Halderman"> <organization/> </author> <author initials="N." surname="Heninger"> <organization/> </author> <author initials="D." surname="Springall"> <organization/> </author> <author initials="E."surname="Thomé">surname="Thome"> <organization/> </author> <author initials="L." surname="Valenta"> <organization/> </author> <author initials="B." surname="VanderSloot"> <organization/> </author><date>n.d.</date><author initials="E." surname="Wustrow"> <organization/> </author> <author initials="S." surname="Zanella-Beguelin"> <organization/> </author> <author initials="P." surname="Zimmerman"> <organization/> </author> <date month="10" year="2015"/> </front> <refcontent>CCS '15: Proceedings of the 22nd ACM SIGSAC Conference on Computer and Communications Security, pp. 5-17</refcontent> <seriesInfo name="DOI" value="10.1145/2810103.2813707"/> </reference> <reference anchor="FREAK" target="https://inria.hal.science/hal-01114250/file/messy-state-of-the-union-oakland15.pdf"> <front> <title>Amessy stateMessy State of theunion:Union: Taming thecomposite state machinesComposite State Machines of TLS</title> <author initials="B." surname="Beurdouche" fullname="Benjamin Beurdouche"> <organization/> </author> <author initials="K." surname="Bhargavan" fullname="Karthikeyan Bhargavan"> <organization/> </author> <author initials="A." surname="Delignat-Lavaud" fullname="Antoine Delignat-Lavaud"> <organization/> </author> <author initials="C." surname="Fournet"fullname="Cédricfullname="Cedric Fournet"> <organization/> </author> <author initials="M." surname="Kohlweiss" fullname="Markulf Kohlweiss"> <organization/> </author> <author initials="A." surname="Pironti" fullname="Alfredo Pironti"> <organization/> </author> <author initials="P.-Y." surname="Strub" fullname="Pierre-Yves Strub"> <organization/> </author> <author initials="J. K." surname="Zinzindohoue" fullname="Jean Karim Zinzindohoue"> <organization/> </author><date>n.d.</date><date month="5" year="2015"/> </front> <refcontent>IEEE Symposium on Security & Privacy 2015</refcontent> <seriesInfo name="HAL ID:" value="hal-01114250"/> </reference> <reference anchor="SLOTH" target="https://inria.hal.science/hal-01244855/file/SLOTH_NDSS16.pdf"> <front> <title>Transcriptcollision attacks:Collision Attacks: BreakingauthenticationAuthentication in TLS, IKE, and SSH</title> <author initials="K." surname="Bhargavan" fullname="Karthikeyan Bhargavan"> <organization/> </author> <author initials="G." surname="Leurent"fullname="Gaëtanfullname="Gaetan Leurent"> <organization/> </author><date>n.d.</date><date month="2" year="2016"/> </front> <refcontent>Network and Distributed System Security Symposium - NDSS 2016</refcontent> <seriesInfo name="DOI" value="10.14722/ndss.2016.23418"/> <seriesInfo name="HAL ID:" value="hal-01244855"/> </reference> <!-- [I-D.ietf-pquip-pqc-engineers] draft-ietf-pquip-pqc-engineers-14 IESG State: EDIT as of 1/5/2026 LONG WAY for author name --> <referenceanchor="I-D.ietf-pquip-pqc-engineers">anchor="I-D.ietf-pquip-pqc-engineers" target="https://datatracker.ietf.org/doc/html/draft-ietf-pquip-pqc-engineers-14"> <front> <title>Post-Quantum Cryptography for Engineers</title> <author fullname="Aritra Banerjee" initials="A." surname="Banerjee"> <organization>Nokia</organization> </author> <author fullname="TirumaleswarReddy.K"Reddy" initials="T."surname="Reddy.K">surname="Reddy"> <organization>Nokia</organization> </author> <author fullname="Dimitrios Schoinianakis" initials="D." surname="Schoinianakis"> <organization>Nokia</organization> </author> <author fullname="Tim Hollebeek" initials="T." surname="Hollebeek"> <organization>DigiCert</organization> </author> <author fullname="Mike Ounsworth" initials="M." surname="Ounsworth"> <organization>Entrust Limited</organization> </author> <dateday="13" month="February"day="25" month="August" year="2025"/><abstract> <t> The advent of a cryptographically relevant quantum computer (CRQC) would render state-of-the-art, traditional public-key algorithms deployed today obsolete, as the mathematical assumptions underpinning their security would no longer hold. To address this, protocols and infrastructure must transition to post-quantum algorithms, which are designed to resist both traditional and quantum attacks. This document explains why engineers need to be aware of and understand post-quantum cryptography (PQC), detailing the impact of CRQCs on existing systems and the challenges involved in transitioning to post-quantum algorithms. Unlike previous cryptographic updates, this shift may require significant protocol redesign due to the unique properties of post-quantum algorithms. </t> </abstract></front> <seriesInfo name="Internet-Draft"value="draft-ietf-pquip-pqc-engineers-09"/>value="draft-ietf-pquip-pqc-engineers-14"/> </reference><reference anchor="RFC5746"> <front> <title>Transport Layer Security (TLS) Renegotiation Indication Extension</title> <author fullname="E. Rescorla" initials="E." surname="Rescorla"/> <author fullname="M. Ray" initials="M." surname="Ray"/> <author fullname="S. Dispensa" initials="S." surname="Dispensa"/> <author fullname="N. Oskov" initials="N." surname="Oskov"/> <date month="February" year="2010"/> <abstract> <t>Secure Socket Layer (SSL) and Transport Layer Security (TLS) renegotiation are vulnerable to an attack in which the attacker forms a TLS connection with the target server, injects content of his choice, and then splices in a new TLS connection from a client. The server treats the client's initial TLS handshake as a renegotiation and thus believes that the initial data transmitted by the attacker is from the same entity<!-- [I-D.ietf-tls-deprecate-obsolete-kex] draft-ietf-tls-deprecate-obsolete-kex-06 IESG State: IESG Evaluation asthe subsequent client data. This specification defines a TLS extension to cryptographically tie renegotiations to the TLS connections they are being performed over, thus preventing this attack. [STANDARDS-TRACK]</t> </abstract> </front> <seriesInfo name="RFC" value="5746"/> <seriesInfo name="DOI" value="10.17487/RFC5746"/> </reference> <reference anchor="I-D.ietf-tls-deprecate-obsolete-kex"> <front> <title>Deprecating Obsolete Key Exchange Methods in TLS 1.2</title> <author fullname="Carrick Bartle" initials="C." surname="Bartle"> <organization>Roblox</organization> </author> <author fullname="Nimrod Aviram" initials="N." surname="Aviram"> </author> <date day="3" month="September" year="2024"/> <abstract> <t> This document deprecates the use of RSA key exchange and Diffie Hellman over a finite field in TLS 1.2, and discourages the use of static elliptic curve Diffie Hellman cipher suites. Note that these prescriptions apply only to TLS 1.2 since TLS 1.0 and 1.1 are deprecated by RFC 8996 and TLS 1.3 either does not use the affected algorithm or does not share the relevant configuration options. This document updates RFCs 9325, 4346, 5246, 4162, 6347, 5932, 5288, 6209, 6367, 8422, 5289, 5469, 4785, 4279, 5487, 6655, and 7905. </t> </abstract> </front> <seriesInfo name="Internet-Draft" value="draft-ietf-tls-deprecate-obsolete-kex-05"/> </reference> <reference anchor="RFC7465"> <front> <title>Prohibiting RC4 Cipher Suites</title> <author fullname="A. Popov" initials="A." surname="Popov"/> <date month="February" year="2015"/> <abstract> <t>This document requires that Transport Layer Security (TLS) clients and servers never negotiate the useofRC4 cipher suites when they establish connections. This applies to all TLS versions. This document updates RFCs 5246, 4346, and 2246.</t> </abstract> </front> <seriesInfo name="RFC" value="7465"/> <seriesInfo name="DOI" value="10.17487/RFC7465"/> </reference>1/5/2026 --> <xi:include href="https://bib.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-tls-deprecate-obsolete-kex.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7465.xml"/> </references> </references> </back><!-- ##markdown-source: H4sIAAAAAAAAA81a3XLbRpa+76foVS42mSJBUZIdW5kdh5ZkW2NZVkR5Ms7U VKoJNMmOADSnG5BEu3S1L7K3W3u/DzD7Yvud0w0QoORKUrUXm0oisNE/5/98 5zSGw6GoTJXrQ7lzrm/lhbOVTW3u5QdvyoW8OpvKd7Wv5KX+R22c5oFxsr8j 1Gzm9A2WufBmWOWeX6Sq0gvr1odylq5Evcrw2x/K5/t7T4TIbFqqAqdlTs2r odHVfFhXatjdZH843hO+nhXGe2PLar3C/NOTq1eirIuZdoeCtjwUqS29Ln2N zStXawFi9oVyWoGoqU5rZ6r1jri17nrhbL3C6IYnU8rJapUbEIsj/I641mvM zA6FHNKE+EdeOVV6Q3OakWm9WllX0c/TstLOrrRTM5PjMBqba1XVTntxo8sa REr5Gw6XMjC58yOIpVmvaQ2NF8rkGIeIvidZJdYtaHhhqmU9I+GbdOlV/mkU 5Fn7KMIdIVRdLS2ENcT8eZ3nQe6XWCCnWIFRbKZK84mpOJSTa4XT5JVOl6XN 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