Re:What end-to-end encryption should look like
by oconnor663 on Wednesday April 22, 2020 @04:30PM
(#22949847)
If you already have pairwise E2E encryption working, you can use it to distribute a shared key. It's the first part that's hard.
Re:What end-to-end encryption should look like
by hunter2_ on Thursday April 23, 2020 @12:10AM
(#22952720)
If your video was encrypted once and multicast to all n other participants, couldn't you do it in such a way that it would be decryptable by n different keys that you handed out, one per participant, without anyone knowing other people's decryption keys? There will be n^2 keys total, but only n streams total.
What would be an attack scenario here that wouldn't exist with the entirely infeasible n^2 streams scenario you mentioned? Nobody would be able to use the keys they possess to make an imposter stream.
True E2EE seems like each endpoint would have to have its own key. But the bandwidth realities of group videoconferencing make it entirely infeasible for each participant to be sending a separately encrypted stream to each other participant. So the only realistic solution is for all members to share the same key, which makes everything dependent on the security of the key distribution. But then... is it really E2EE? I'm not sure there's a generally accepted answer here.