ZRTP key continuity check removed from Signal/RedPhone about textsecure

[relyt29]

just curious, what is SAS?

[xmikos]

@f41c0r SAS is Short Authentication String, shared value (those two words displayed on screen while calling with RedPhone/Signal) which both communicating parties should verbally cross-check. With key continuity, it is sufficient to cross-check SAS only in first call (TOFU model - Trust On First Use). But without key continuity, you have to cross-check SAS in every call to avoid potential MITM attack.

[h-2]

I think it would be wise to keep the diff of the websocket-branch absolutely minimal as long as there is a chance of it being merged upstream. Iff this can be ruled out, one should think about a real fork (with potentially different features).

[xmikos]

@h-2 This is really important basic security feature, without it even cSipSimple (or any other SIP client which supports ZRTP) is much more secure than Signal.

[h-2]

@xmikos the other thread suggests that it might be a temporary change. Also I think that as long as we want something from moxie (i.e. to accept the patch) we should not pick other fights with him. Its not very polite or smart ;) We can discuss it afterwards, and ultimately we would want the feature to be active for mainline TS users, as well.

[xmikos]

@h-2 I surely hope that it is only temporary while Signal is in beta. But Moxie didn't write anything to assure us that it is indeed like that. Btw. I don't believe anymore that WebSocket support will ever get merged upstream.