Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add text in Security Consideration regarding the benefits of the 64-byte seed format #69

Merged
48 changes: 45 additions & 3 deletions draft-ietf-lamps-kyber-certificates.md
Original file line number Diff line number Diff line change
Expand Up @@ -75,6 +75,31 @@ normative:
ISO/IEC: 8825-1:2021

informative:
CDM23:
title: "Keeping Up with the KEMs: Stronger Security Notions for KEMs and automated analysis of KEM-based protocols"
target: https://eprint.iacr.org/2023/1933.pdf
date: 2023
author:
-
ins: C. Cremers
name: Cas Cremers
org: CISPA Helmholtz Center for Information Security
-
ins: A. Dax
name: Alexander Dax
org: CISPA Helmholtz Center for Information Security
-
ins: N. Medinger
name: Niklas Medinger
org: CISPA Helmholtz Center for Information Security
KEMMY24:
title: "Unbindable Kemmy Schmidt: ML-KEM is neither MAL-BIND-K-CT nor MAL-BIND-K-PK"
target: https://eprint.iacr.org/2024/523.pdf
date: 2024
author:
-
ins: S. Schmieg
name: Sophie Schmieg
NIST-PQC:
target: https://csrc.nist.gov/projects/post-quantum-cryptography
title: >
Expand Down Expand Up @@ -295,9 +320,26 @@ encoded using the textual encoding defined in {{?RFC7468}}.

# Security Considerations

The Security Considerations section of {{RFC5280}} applies to this specification as well.

For ML-KEM specific security considerations refer to {{?I-D.sfluhrer-cfrg-ml-kem-security-considerations}}.
The Security Considerations section of {{RFC5280}} applies to this
specification as well.

dconnolly marked this conversation as resolved.
Show resolved Hide resolved
For ML-KEM specific security considerations refer to
{{?I-D.sfluhrer-cfrg-ml-kem-security-considerations}}.

dconnolly marked this conversation as resolved.
Show resolved Hide resolved
Per the analysis of the final {{FIPS203}} in {{KEMMY24}}, a compliant
instantiation of ML-KEM is LEAK-BIND-K-PK-secure and LEAK-BIND-K-CT-secure
when using the expanded key format, but not MAL-BIND-K-PK-secure nor
MAL-BIND-K-CT-secure. This means that the computed shared secret binds to the
encapsulation key used to compute it against a malicious adversary that has
access to leaked, honestly-generated key material but is not capable of
manufacturing maliciously generated keypairs. This binding to the
encapsulation key broadly protects against re-encapsulation attacks but not
completely.

Using the 64-byte seed format provides a step up in binding security by
mitigating an attack enabled by the hash of the public encapsulation key
stored in the expanded private decapsulation key format, providing
MAL-BIND-K-CT security and LEAK-BIND-K-PK security.

# IANA Considerations

Expand Down