Adding a nounce before hashing as covert channel

[andrewg]

On 2024-12-12 11:58, Wiktor Kwapisiewicz wrote:
> 
> On 12.12.2024 11:43, Andrew Gallagher via Gnupg-devel wrote:
>> It should be noted that the salt in v6 signatures also helps to 
>> protect against fault-based attacks. 
>> See https://eprint.iacr.org/2017/1014
> 
> I'm not entirely sure that the v6 salt helps in this case - it 
> influences the final digest but the fault attack then operates on that 
> new digest. I've read section 9. Countermeasures and couldn't find any 
> mention of salt being effective.

Fault attacks require the generation of multiple signatures over the 
same message digest. With an unsalted signature, it is sufficient to 
induce a victim to sign the same message twice with the same timestamp. 
With a salted signature, it is vanishingly improbable that the same 
digest will ever be produced.

A