Privacy

40898 readers

1296 users here now

A place to discuss privacy and freedom in the digital world.

Privacy has become a very important issue in modern society, with companies and governments constantly abusing their power, more and more people are waking up to the importance of digital privacy.

In this community everyone is welcome to post links and discuss topics related to privacy.

Some Rules

Posting a link to a website containing tracking isn't great, if contents of the website are behind a paywall maybe copy them into the post
Don't promote proprietary software
Try to keep things on topic
If you have a question, please try searching for previous discussions, maybe it has already been answered
Reposts are fine, but should have at least a couple of weeks in between so that the post can reach a new audience
Be nice :)

Related communities

much thanks to @gary_host_laptop for the logo design :)

founded 5 years ago

MODERATORS

Revery: v0 of a secure messaging protocol (github.com)

submitted 3 weeks ago* (last edited 3 weeks ago) by slugr@leminal.space to c/privacy@lemmy.ml

8 comments fedilink hide all child comments

i started a (very niche) private messaging protocol & little CLI app demo. i’m no security expert, so any feedback or questions would be appreciated.

the gist is an ephemeral message exchange without identities. the goal is ultimate deniability.

the interesting (and weird) part is that messages are encrypted but not authenticated. this means an imposter could show up if they know the shared secret. otoh this means you can deny anything you say.

all 11 comments

sorted by: hot top controversial new old

[–] slugr@leminal.space 6 points 3 weeks ago

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!

[–] cipherd@lemmy.ml 5 points 3 weeks ago (2 children)

Couldn't you use HMAC with shared secret key to authenticate messages while keeping plausible deniability? Since the key is only supposed to be known to the 2 parties, the recipient can deduce that a message was actually sent by the sender if he did not create it himself. I think that's what OTR was using.

[–] slugr@leminal.space 4 points 3 weeks ago

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!

[–] gaylord_fartmaster@lemmy.world 2 points 3 weeks ago (1 children)

Same encryption key can create "alternative facts" - impossible to prove which conversation really happened

Can you elaborate on what this means?

[–] slugr@leminal.space 1 points 3 weeks ago

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.