Follow these steps to obtain a public key, and sign the key after confirming
its authenticity.
Select the nickname of the peer on the member list whose public key you
would like to obtain.
Go to "PGP" menu -> "Import The Key".
The key is sent from the peer, and imported to your key ring.
The following window appears.
Confirm that the following items are correct on the window.
[Name]
The name and the e-mail address of the peer.
You have to confirm that these are correct.
[Fingerprint]
The fingerprint of the public key.
You have to confirm that it is identical with the one the peer
has given to you by a different means.
In case you can safely obtain the color pattern from the peer
(such as when their laptop is next to you), it would suffice to see
if the two color patterns look alike.
Click on "Sign" button if you are sure that the public key belongs to the
peer.
A window appears to ask you to type your GnuPG passphrase.