Plans for Post-Quantum Cryptography in GnuPG

[Robert J. Hansen]

> Another threat based on similar use of time as an attack tool is to
> "fake signature later and pretend it is a long term contract signed
> 25 years earlier"

This is not a serious threat.

"Your Honor, there is no evidence in the historical record to support 
the claim this contract was entered into. None. We request discovery on 
plaintiff's computers and accounts. Our digital forensics nerds will get 
to the bottom of this. With the fact the algorithm used to allegedly 
sign this contract a quarter-century ago can be trivially forged today, 
we repudiate the signature, allege there has been fraud on this court, 
and ask the court to get involved."

Lawyers repudiate forged documents all the time. They're pretty good at it.