GnuPG was warning me each time I use someone's key:
There is no assurance this key belongs to the named user
Use this key anyway? (y/N)
To get rid of this warning I signed his key:
gpg --sign-key [email]
Then the first time I used GPG I got this message:
gpg: checking the trustdb
gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model
gpg: depth: 0 valid: 1 signed: 1 trust: 0-, 0q, 0n, 0m, 0f, 1u
gpg: depth: 1 valid: 1 signed: 0 trust: 1-, 0q, 0n, 0m, 0f, 0u
But after the first usage no longer this message. What is the meaning of this message? Which "trustdb" is it checking? Something on the internet or what?