[grabcocque]

This just goes to show the importance of picking sound defaults. WhatsApp gets this horribly wrong. Regardless of whether it's a backdoor, their default behaviour is dangerous because it leaves users vulnerable to MITM attacks.

Let's not get hung up on semantics, and focus on the HARM.

[rocqua]

I should point out that even with the 'correct' setting (which isn't default) whatsapp will still re-encrypt and re-transmit any unsent messages under the new key. All the 'correct' setting does is notify you of the key change.

The article is factually wrong on this.