WhatsApp Blocking Encrypted Calls to All Saudi Numbers

Post by Jarwain » Thu, Jul 14, 2016, 4:35 AM UTC

moxie wrote: post #50

eridius wrote: post #14

Earlier quoted context omitted.

The gist explicitly claims that's not possible. Specifically, it claims that there's no way for the Saudi teleco to distinguish encrypted phone calls from encrypted messages, and since you can send encrypted messages to Saudi users, there's no technical reason why you can't also call them. The implication is that if WhatsApp did allow the calls, the Saudi telecos might block both calls and messages (since they can't…

The author is incorrect. While Signal Protocol is used to communicate an SRTP master secret and a session id, the clients still need to do an ICE handshake in order to establish communication with each other before the responder can even ring. It is very straightforward for SA to block that traffic, and it is established fact that they do. It seems as if WhatsApp is short circuiting this frustrating series of timeout…

Post by nkobeissi » Thu, Jul 14, 2016, 5:15 AM UTC

moxie wrote: post #50

eridius wrote: post #14

Earlier quoted context omitted.

The gist explicitly claims that's not possible. Specifically, it claims that there's no way for the Saudi teleco to distinguish encrypted phone calls from encrypted messages, and since you can send encrypted messages to Saudi users, there's no technical reason why you can't also call them. The implication is that if WhatsApp did allow the calls, the Saudi telecos might block both calls and messages (since they can't…

The author is incorrect. While Signal Protocol is used to communicate an SRTP master secret and a session id, the clients still need to do an ICE handshake in order to establish communication with each other before the responder can even ring. It is very straightforward for SA to block that traffic, and it is established fact that they do. It seems as if WhatsApp is short circuiting this frustrating series of timeout…

Post by Canada » Thu, Jul 14, 2016, 9:40 AM UTC

amluto wrote: post #65

Canada wrote: post #42

Earlier quoted context omitted.

ZRTP is a key agreement protocol. It sets the key for SRTP, which is ultimately responsible for securing the RTP payload. SRTP keys can also be set by the signaling server, but then the encryption is not end to end. There's another protocol called SDP to handle this Signal does use ZRTP. It just doesn't use SIP. ZRTP is currently the best choice for voice.

> ZRTP is currently the best choice for voice. I beg to differ. ZRTP is currently the best choice for voice when the caller and callee share no key material to begin with. In the context of Signal-the-app, the caller and callee often do share key material, but the protocol (to the best of my knowledge) doesn't bother to use that key material to authenticate the voice channel. This means that two users with the abilit…

Post by spacefight » Thu, Jul 14, 2016, 10:41 AM UTC

s_q_b wrote: post #52

spacefight wrote: post #43

This case is a brilliant reminder to anyone working in deep packet inspection/blocking/filtering tech that your work negatively affects the safety of millions of people in such countries at once.

This case is a brilliant reminder to anyone working in fiber optics that your work negatively affects the safety of millions of people in such countries at once. But seriously, deep packet inspection is evil now? It's an extremely useful security tool.

Post by s_q_b » Thu, Jul 14, 2016, 1:20 PM UTC

spacefight wrote: post #77

s_q_b wrote: post #52

Earlier quoted context omitted.

This case is a brilliant reminder to anyone working in fiber optics that your work negatively affects the safety of millions of people in such countries at once. But seriously, deep packet inspection is evil now? It's an extremely useful security tool.

Why do you misquote me? Yes, it might be useful for some folks - it's really bad for others. People have died because of oppressive regimes targeting dissidents that way.