On Fri, Feb 27, 2026 at 07:05:38AM -0800, [email protected] wrote:
> Internet-Draft draft-ietf-jose-pq-composite-sigs-01.txt is now available. It
> is a work item of the Javascript Object Signing and Encryption (JOSE) WG of
> the IETF.
> 
>    Title:   PQ/T Hybrid Composite Signatures for JOSE and COSE
>    Authors: Lucas Prabel
>             Sun Shuzhou
>             John Gray
>             Tirumaleswar Reddy
>    Name:    draft-ietf-jose-pq-composite-sigs-01.txt
>    Pages:   29
>    Dates:   2026-02-27

Some comments:

- There are some overlong lines, making side-by-side diff difficult
  to read.


- "Point compression for the ECDSA or EdDSA component is not performed
  for the AKP JSON Web Key Type but can be performed for the AKP COSE
  Key Type."

  For ECDSA, performing the optional point compression is not compatible
  with using SerializePublicKey()/DeserializePublicKey(), since those
  functions always use the uncompressed form.

  And for EdDSA, optional point compression is meaningless, because
  EdDSA always performs point compression.

  All publically computable transforms are trivially secure.


- Using SerializeSignatureValue()/DeserializeSignatureValue() uses ASN.1
  for ECDSA signatures, which is undesirable (especially in COSE), as it
  adds unnecessary complexity (in a very sensitive place).

  All publically computable transforms are trivially secure.


- Also, SerializePrivateKey()/DeserializePrivateKey() uses ASN.1 for
  ECDSA keys, which is undesirable (especially in COSE).

  This is also publically computable as transform, even if it is done
  on private data.


- A security concern is that implementing these hybrids may interfere
  with removing unsafe signature algorithms when Q-Day arrives. It is
  very difficult to ensure insecure signatures are not used without
  completely ripping out the implementation.




-Ilari

_______________________________________________
jose mailing list -- [email protected]
To unsubscribe send an email to [email protected]

Reply via email to