also, i’m new to lemmy, so if there are any communities i should cross post this to that may be interested, please let me know!

neovim. i much prefer the motions of helix, but there’s just some plugins i can’t live without.

ooh, i’ll have to think through it, but it sounds like that’d add message integrity without sacrificing deniability. also wouldn’t be much to add. appreciate the feedback!

interesting point! i chose symmetric shared key because it means you can’t prove who sent what message.

the shared secret does add some authentication, which i think is necessary. the goal is it only creates enough to be practical (a random person can’t eavesdrop), but not enough to prove things. messages themselves still aren’t authenticated by any one person.

that’s on the person forging, it’s not doing any crazy forging on its own. it could, but like you said, i think that’d run into an issue of not being believable by not matching the personas and conversation context. that said, my belief is you probably don’t need perfect forgeries, just the ability to create plausible ones.

there’s still lots of open questions around usability and the practical deniability of it, just want to make sure the crypto side makes sense.

sure!

during or after a conversation, anyone with the keys can create fake transcripts by creating messages with the same metadata, same nonce, different content.

because of this, no transcript can be proven to be the correct transcript. the trade-off is you don’t get forward secrecy on the per-message level, but you get it per-conversation.

another detail is that there is no identity, so all the above aside, there’s also no way to prove who sent which message.

you’re not wrong, but that’s just the trade off that has to be made, i think. it’s the only way i can think to do it, at least. need -some- authentication for practical usability.

your gpg example removes the deniability since it proves who wrote the message.