adding TOFU/POP to GnuPG

Robert J. Hansen rjh at
Fri Mar 14 17:25:36 CET 2014

> One simple idea has proven quite useful in improving security in other
> protocols, but remains unimplemented in OpenPGP/GnuPG (as far as I know):
> Trust On First Use/Persistence of Pseudonym (TOFU/POP).

Googling for "TOFU/POP" doesn't turn up anything in the first two  
pages of Google results that isn't associated with you.  My initial  
reaction is, "until it becomes more widely known, let's not do this --  
GnuPG is a place for established technologies, not a place  
technologies go to become established."

> * full SSH style TOFU/POP keyring: the process of adding a key to your local
> keyring marks it as trusted.  signatures also mark keys as trusted

You've just made signatures effectively meaningless.  The only way a  
signature can have meaning is if it's on a certificate that for  
whatever reason isn't part of your local keyring.

> * or a more GnuPG style: adding a key to the local keyring adds some trust,
> but not as much as a signature.

You're just redefining what "untrusted" means.

> While this does not provide as strong a verification as an OpenPGP signature
> on a key, it is also much more likely to actually happen, and does provide a
> benefit.

What benefit?  It offers nothing that "trust-model always" doesn't.   
If you want to always trust certificates in your keyring, then set  
your gpg.conf accordingly.

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