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Voice Calls: Secure, Crystal-Clear, AI-Powered

telegram.org

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Re: Voice Calls: Secure, Crystal-Clear, AI-Powered

#151

Earlier quoted context omitted.

Sounds like marketing speech for variable bitrate encoding and/or adjusting compression aggressiveness.

> variable bitrate encoding I hope not... VBR can easily leak all sorts of information (including the actual content of the conversation)

Correct, last article I recall reading about deciphering VBR from packet size alone was something in the neighborhood of 50% success rate.

Re: Voice Calls: Secure, Crystal-Clear, AI-Powered

#152
post #131

I will definitely try this because I have trouble with all other voice chat services including Skype, WhatsApp and Hangouts. Often one of those three will work but not always. But the most annoying problem with any internet voice chat is not so much the quality but the latency. Landline phones have noticeably lower voice quality but one can still enjoy a conversation perfectly well. High latency, on the other hand, a…

>I always see these services talking about "crystal clear quality", but never latency, which is a shame. Maybe there is simply nothing they can do about it. I've noticed latency get worse and worse on the Internet since I started using it in the 90s and nobody seems to talk about it. Well, the first problem at home is likely your wireless. Live in an apartment and you can pick up 30 other routers in your wifi search.…

For anyone interested, MIT's systems class has students read two different papers on buffer bloat:

http://web.mit.edu/6.033/www/papers/gettys.pdf

http://web.mit.edu/6.033/www/papers/allman.pdf

Re: Voice Calls: Secure, Crystal-Clear, AI-Powered

#153
post #87

Earlier quoted context omitted.

It looks like in [1] that each device registered to a user has a device_key and when an encrypted message is sent, they user's public devices keys are requested and the message is encrypted for each device. New devices can't see old messages. [1] https://matrix.org/docs/guides/e2e_implementation.html

The message isn't encrypted for each device; the message is encrypted once for the room, as part of a 'session' of messages - and then the key data for that session is shared with the devices who are allowed to read it. Thus you can share old session key data with other devices if you want, meaning that new devices /can/ see old messages, although we're still working through the UX for that. (Currently the only way t…

Thanks—so there's another layer of encryption over the ever changing (Megolm) key that encrypts the room, if I understand this. Looks like I simplified too much.

Re: Voice Calls: Secure, Crystal-Clear, AI-Powered

#154
This is awesome.. I have been trying to video chat with somebody more overseas. Whatsapp video, facebook video, skype, seems like the only thing that works for us right now is Duo.

Bad thing: this tech is trapped in Telegram which is quite political of an app. I wish they'd break it out into something like duo.

Re: Voice Calls: Secure, Crystal-Clear, AI-Powered

#155

Earlier quoted context omitted.

> I've noticed latency get worse and worse on the Internet since I started using it in the 90s and nobody seems to talk about it. You're remembering incorrectly then. Dialup latency was in the range of hundreds of ms. Early high speed internet access also had higher latency than modern connections. If you have latency problems it's likely a problem with your hardware.

I don't remember dialup latency. I only remember it having low bandwidth. I'm talking about ADSL latency in the 90s.

Latency for a 56k modem was 180ms. Latency for a voice call on the same line was _much_ smaller. AFAICT, latency from my games console television to my TV is much higher...

Re: Voice Calls: Secure, Crystal-Clear, AI-Powered

#156
post #73

Does anyone have an opinion on the new "three-message modification of the standard DH key exchange" they introduced for calls? From their API doc: https://core.telegram.org/api/end-to-end/voice-calls#key-ver... > Party A will generate a shared key with B — or whoever pretends to be B — without having a second chance to change its exponent a depending on the value g_b received from the other side; and the impostor wil…

That just sounds like ZRTP to me, from the short description in your comment.

If it is it will be interesting to see if they managed to get zrtp correct. It is a pretty complicated protocol with many use cases.

Re: Voice Calls: Secure, Crystal-Clear, AI-Powered

#157

Earlier quoted context omitted.

> variable bitrate encoding I hope not... VBR can easily leak all sorts of information (including the actual content of the conversation)

Correct, last article I recall reading about deciphering VBR from packet size alone was something in the neighborhood of 50% success rate.

Then why not compress really efficiently by just transmitting packet sizes?

Re: Voice Calls: Secure, Crystal-Clear, AI-Powered

#159
post #115

Earlier quoted context omitted.

Signal and WhatsApp both support multi-device encrypted chats. Signal is better than WhatsApp in this respect as your primary device doesn't need to be online for it to work.

Signal multi-device support is very limited. Doesn't support multiple mobile devices. Primary device must be a phone, all others must be desktop computers with Chrome.

True, though that's a gap in UI rather than a constraint of the protocol.
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