http://bkg5ofjslnbyqvu55sjonpdyp3wmfsgq23u7vpk3wxn7ewgdeocpgwid.onion?page=article&article=How+to+Safely+Share+Encrypted+Files+Over+Public+Channels.html
For example, if you share the encrypted file over email, send the key via a secure messaging app like Signal or an in-person conversation. Time-Limited Sharing : If possible, share the decryption key for a limited time.