That's a bit misleading. WhatsApp uses Signal's end-to-end encryption scheme, but not Signal's networking protocol. It's still proprietary. Otherwise, we could have cross-messaging between Signal and Whatsapp.
WhatsApp just implemented cross messaging using the open Signal Protocol forced by the EU. We will see if the Signal messenger enables interop with WhatsApp, they are not forced to do this.
That's a bit misleading. WhatsApp uses Signal's end-to-end encryption scheme, but not Signal's networking protocol. It's still proprietary. Otherwise, we could have cross-messaging between Signal and Whatsapp.
WhatsApp just implemented cross messaging using the open Signal Protocol forced by the EU. We will see if the Signal messenger enables interop with WhatsApp, they are not forced to do this.
Pedantic: I think you meant to say open whisper protocol, the end to end protocol which is Whatsapp copied from Signal.
The name of the protocol is "Signal".