Not trivially. But with painstaking reverse engineering you could prove this. And people have, so you're not exclusively just taking Meta's word. The fact that Pegasus malware relied on remote code execution vuln to run malware on your phone to extract WhatsApp messages, really suggests that the E2EE works. If it wasn't E2EE, then the makers of Pegasus could have just intercepted traffic to get your messages.
Academics have also reverse engineered it as well, and though there are some weakness it's not a lie that WhatsApp is E2EE. Here's some I just found:
Academics have also reverse engineered it as well, and though there are some weakness it's not a lie that WhatsApp is E2EE. Here's some I just found:
- https://eprint.iacr.org/2025/794.pdf
- https://i.blackhat.com/USA-19/Wednesday/us-19-Zaikin-Reverse...