PGP encryption.

We have a trading partner who wants to encrypt a file using PGP
encryption. Then he will send it to us via our SFTP site (set up using
Linoma software). Once the transmission is complete we have to decrypt
it. There's two questions that first pop to mind:
1 - Are PGP keys like SSL keys where you get them from a trusted source
for a fee or are they something that you get from some open source type
site for nothing?
2 - How does one decrypt a file on the i that is PGP encrypted?


Rob Berendt