It's used for encryption, but I'll let wikipee do the explaining, because after reading this, I'm not altogether sure of its functionality. It seems to be an extra level of security that allows you to authenticate the public key which is used for encrypting a message. I think.
Thanks. I'm wondering how someone would use it or why they'd use it to get in touch with him.
If I understand it correctly, you don't use it to contact him. If he wants to send you an encrypted message, he has to share his public key with you. You use the fingerprint on your end to make sure the public key is valid. If it is, you then use the public key to decrypt the message they sent you.
I think. I've used public keys before, but have never used the fingerprint. Frankly I don't quite see the point, but I'm not that familiar with encryption practices other than the basics.
What on earth is that? I was looking at someone's individual professional website, and after the email address it says, "The fingerprint for my public key is ..." then a long alpha-numeric hypertext.