Hi Tim,

> Op 23 sep 2025, om 03:49 heeft Tim Bray <[email protected]> het volgende 
> geschreven:
> 
> Just out of curiosity, is the chance of failure easy to compute? E.g. chance 
> of a random-UUID collision is something like 2.7 * 10**-18
> 

It’s part of the properties of ML-KEM (because it’s a security-related 
parameter). It’s specified in Table 1 of the FIPS: for ML-KEM 512, the failure 
rate is 2^-138, the others similarly cryptographically negligible.

Realistically, ML-KEM decapsulation failures will never happen before the heat 
death of the universe or something similarly silly.

Cheers,

Thom

> -T
> 
> On Mon, Sep 22, 2025, 6:13 p.m. Filippo Valsorda <[email protected] 
> <mailto:[email protected]>> wrote:
>> Strong agree. Failure probabilities lower than the chance of hardware 
>> failure can only be ignored. Anything else is needless complexity.
>> 
>> (I believe we’d also avoid handling the DSA signature failure case, if we 
>> were to write it up today.)
>> 
>> 2025-09-22 21:03 GMT+02:00 Eric Rescorla <[email protected] 
>> <mailto:[email protected]>>:
>>> Hi folks,
>>> 
>>> I see that the hybrid doc continues to have this text:
>>> 
>>> Failures. Some post-quantum key exchange algorithms, including ML-KEM 
>>> [NIST-FIPS-203 
>>> <https://www.ietf.org/archive/id/draft-ietf-tls-hybrid-design-16.html#NIST-FIPS-203>],
>>>  have non-zero probability of failure, meaning two honest parties may 
>>> derive different shared secrets. This would cause a handshake failure. 
>>> ML-KEM has a cryptographically small failure rate; if other algorithms are 
>>> used, implementers should be aware of the potential of handshake failure. 
>>> Clients MAY retry if a failure is encountered.
>>> 
>>> There was extensive discussion about this for the pure ML-KEM draft, and my 
>>> sense was the sentiment was that this should not be discussed, at least for 
>>> ML-KEM. I think we should remove
>>> this whole section.
>>> 
>>> -Ekr
>>> 
>>> _______________________________________________
>>> TLS mailing list -- [email protected] <mailto:[email protected]>
>>> To unsubscribe send an email to [email protected] 
>>> <mailto:[email protected]>
>>> 
>> 
>> _______________________________________________
>> TLS mailing list -- [email protected] <mailto:[email protected]>
>> To unsubscribe send an email to [email protected] 
>> <mailto:[email protected]>
> _______________________________________________
> TLS mailing list -- [email protected]
> To unsubscribe send an email to [email protected]

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

Reply via email to