Looking for an end-to-end encrypted video messenger as an alternative to Zoom, especially one which allows others to join the call without creating an account, to make it easy on external conference attendees.
I’ve heard of Jitsi, Jami, Wire, Threema, Briefing, Element (/matrix?), and Signal – but haven’t seen a concrete answer on the benefits of each against the others.
Your recommendations, please! Thanks 
Jitsi is basically like zoom but open source (unfortunately E2EE seems a bit limited at the moment Does Jitsi support end-to-end encryption? - Jitsi). You could host your own instance though. Element uses Jitsi FOR THE MOMENT, but will soon be switching to a more secure and private E2EE solution using a using a native Matrix solution. I dont have experience with the other ones.
which allows others to join the call without creating an account
Wire & Jitsi/Element have this option. But Wire is commercial service, it’s free for teams up to 5 users.
I don’t see any limitations in the e2ee for Jitsi. You say it’s limited, what’s that mean?
I’m guessing they were referring to this paragraph from the link they provided in their previous comment.
In the case of multiparty meetings all audio and video traffic is still encrypted on the network (again, using DTLS-SRTP). This outer layer of DTLS-SRTP encryption is removed while packets are traversing Jitsi Videobridge; however they are never stored to any persistent storage and only live in memory while being routed to other participants in the meeting.
IF I understood the link correctly, It sounds like 1 to 1 conversations are E2E encrypted, but multiparty conversations are not E2EE
There is a new project underway that aims to make decentralised P2P group calls called element call.
You can check it out here (altho in the current testing stage of it they claim they turn off encryption while they test the stability but will enable it again)
This is different from the 1:1 calls in element desktop/apps and element using jitsi. Element call after being stable will get integrated as the primary group video call system.
It says that e2ee doesnt work qith firefox if i remember correctly… Its been a while
They said that they have disabled encryption completely while they test the system, but once the application is stable, they plan to enable it again and since it’s browser based it should work on any browser once enabled including firefox
Looks interesting. but I cannot find any mentions of it being open source. Do you have any idea?
That’s not what the page is saying. Your quote is from the part of the page that talks about the protections that Jitsi employs when E2EE mode is not used.
There’s also an interesting talk here, that doesn’t just apply to Jitsi but E2EE in general: The pitfalls of end-to-end encryption - Jitsi It makes a point which is not new but that we shouldn’t overlook. Just having an “E2EE toggle” somewhere or “E2EE support” baked into the software product somehow does not necessarily mean it’s therefore completely safe. You still have to look exactly into who you are trusting with what. And in some cases, it might therefore better to self-host the Jitsi instance. But if you’re doing that and presumably can 100% trust your instance, then of course also the question arises, what benefit does E2EE offer at that point vs just transfer encryption?
Anyway, Jitsi does have E2EE if you enable it, regardless of the number of participants. It will disable some features that require the server having access to the video data (duh!). Jitsi E2EE only works with Browsers supporting WebRTC Insertable Streams: True End-to-End Encryption with WebRTC Insertable Streams - webrtcHacks
Indeed that just screams privacy-focused:
If I show that screenshot to rms he wouldn’t be able to sleep for a fortnight.
Edit: Just doxxed my time zone. RIP 
that’s what I meant: Firefox doesn’t have insertable streams last time I checked
OpenTalk is working on E2EE. But even without it, I would still consider it if other requirements are met
