> [Durov] The encryption of Signal (=WhatsApp, FB) was funded by the US Government. I predict a backdoor will be found there within 5 years from now...To emphasize even more why this is silly: nobody from the government (well, at least nobody who has said they're from the US or any other government) was involved with the actual development of the Signal Protocol. It was just funded by the government, through the Open Technology Fund, a project of Radio Free Asia (which is itself under the Department of State; the OTF was largely an initiative of Sec. Clinton). This is an extremely different part of the government from either NIST or any of the three-letter agencies.
There has been exactly one backdoor found in crypto relating to the US government (Dual_EC_DRBG), and it was in crypto developed by the NSA and basically pushed into a standard. It was also crypto that looked extremely suspicious, immediately, to any cryptographer who looked at it: it had a contrived design for no good reason, ran much slower than the existing options in the space, and appeared to support a backdoor. A lot of people have looked at the Signal Protocol and found nothing like this.
The US government has been accused of hiding backdoors before in one case, DES. It turned out that they were hiding a way of strengthening DES against an attack that was not yet public (differential cryptanalysis) but had been discovered by the NSA. Nothing like this happened to Signal: the developers were not told by the government "Great, just use these S-boxes instead."
(In fact, it occurs to me that there's not much room in Signal for a backdoor along the above lines: no S-boxes, no constants, etc. The closest it gets to that is picking Curve25519 and Curve448, both of which are well-known curves, predating Signal, with simple mathematical descriptions that make them essentially impossible to have backdoors. Perhaps he means that the Signal software is backdoored? But that wouldn't make sense with the reference to WhatsApp and Facebook, and also is a much more easily disprovable assertion than that crypto is backdoored.)
The US government also, of course, weakened crypto with the ridiculous export rules of the '90s. But that wasn't a backdoor, and they were pretty explicit that the intention was to weaken crypto. The OTF has no such motivation here; their goal was to produce secure tools that can be used by dissidents around the world, and intentionally-weakened crypto would be dangerous in such a context.