| Internet-Draft | connolly-tls-mlkem-key-agreement | March 2024 |
| Connolly | Expires 5 September 2024 | [Page] |
This memo defines ML-KEM as a standalone NamedGroup for use in TLS 1.3
to achieve post-quantum key agreement.¶
This note is to be removed before publishing as an RFC.¶
Status information for this document may be found at https://datatracker.ietf.org/doc/draft-connolly-tls-mlkem-key-agreement/.¶
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Source for this draft and an issue tracker can be found at https://github.com/dconnolly/draft-tls-mlkem-key-agreement.¶
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FIPS 203 standard (ML-KEM) is a new FIPS / CNSA 2.0 standard for post-quantum key agreement via lattice-based key establishment mechanism (KEM). Having a fully post-quantum (not hybrid) FIPS-compliant key agreement option for TLS 1.3 is necessary for eventual movement beyond hybrids and for users that need to be fully post-quantum sooner than later.¶
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.¶
We align with [hybrid] except that instead of joining ECDH options
with a KEM, we just have the KEM as a NamedGroup.¶
TLS 1.3's key schedule commits to the the ML-KEM encapsulation key and the encapsulated shared secret ciphertext, providing resilience against re-encapsulation attacks against KEMs used for key agreement.¶
ML-KEM is MAL-BIND-K-PK-secure but only LEAK-BIND-K-CT and LEAK-BIND-K,PK-CT-secure, but because of the inclusion of the ML-KEM ciphertext in the TLS 1.3 key schedule there is no concern of malicious tampering (MAL) adversaries, not just honestly-generated but leaked key pairs (LEAK adversaries). The same is true of other KEMs with weaker binding properties, even if they were to have more constraints for secure use in contexts outside of TLS 1.3 handshake key agreement.These computational binding properties for KEMs were formalized in [CDM23].¶
This document requests/registers two new entries to the TLS Named Group (or Supported Group) registry, according to the procedures in Section 6 of [tlsiana].¶
TODO acknowledge.¶