Gnu Privacy Guard: basic gpg techniques

Import a key when you know the fingerprint:

gpg --keyserver pgp.mit.edu --recv-keys FINGERPRINT

Import a key by email address:

gpg --keyserver pgp.mit.edu --search-keys EMAILADDRESS

Trust the key:

( fingerprint=FINGERPRINT ; echo $fingerprint":6:" | gpg2 --import-ownertrust )

Encrypt a file:
* See this page: GPG Quick Start

Update expired key:
* See this page: [Howto] Changing the expiry date of GPG keys