Yeah, here's what it actually looks like with the command line client, which is more verbose than the GUIs. I've removed the other people's key IDs and email addresses in case they don't want that public. First, I encrypt and decrypt normally: Then I encrypt with throw-keyid and decrypt: As you can see, I as the recipient would have no idea that the message was also encrypted to Nightcrawler and SelfSovereignty, even though I have their public keys.