Hi,

I just noticed that RFC8152bis has the recommendation:

"Implementations SHOULD use a deterministic version of ECDSA such as the one 
defined in [RFC6979]."

I don't think this is a good recommendation for IoT devices. In the last 5 
years, i.e. after work on RFC 8152 started, there has been a large amount of 
academic papers showing that purely deterministic ECC algorithms in accesable 
IoT devices suffers from side-channel and fault injection attacks. For a list 
of papers see e.g. Seciton 1 of 
https://tools.ietf.org/html/draft-mattsson-cfrg-det-sigs-with-noise-02

I would suggest changing the SHOULD to MAY, but I know the draft is already in 
RFC editors que...

Alternatively (or additionally) the draft could add some non-normative security 
consideration regarding deterministic ECC signatures.

"Deterministic elliptic-curve signatures such as deterministic ECDSA
and EdDSA have gained popularity over randomized ECDSA as their
security do not depend on a source of high-quality randomness.
Recent research has however found that implementations of these
signature algorithms may be vulnerable to certain side-channel and
fault injection attacks due to their determinism. See e.g. Section 1 of
[draft-mattsson-cfrg-det-sigs-with-noise] for a list of attack papers."

Recommending deterministic ECDSA for IoT devices without any security 
considerations would not be good.

FYI, CFRG has discussed and agreed that this is a problem.

Cheers,
John

_______________________________________________
COSE mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/cose

Reply via email to