http://bkg5ofjslnbyqvu55sjonpdyp3wmfsgq23u7vpk3wxn7ewgdeocpgwid.onion?page=article&article=Secure+Collaboration%3A+Encrypting+Group+Communication+with+GPG.html
Encrypting for Multiple Recipients Encrypting a message for a group is as straightforward as encrypting for a single user, with the added step of specifying each recipient’s public key. Let’s say you want to share a confidential document or message with a group of colleagues: Alice, Bob, and Charlie.