Is WhatsApp end-to-end encrypted?
Yes — WhatsApp end-to-end encrypts every chat by default, using Signal Protocol (X3DH + Double Ratchet, Curve25519, AES-256-CBC + HMAC-SHA256); Sender Keys for groups. Its handshake is not yet post-quantum, so traffic captured today could be decrypted later by a quantum computer.
End-to-end encryption protects message contents — but not necessarily metadata. WhatsApp's metadata model is Minimal: messages are E2EE, but Meta retains extensive metadata (phone number, contacts, device/IP, timestamps, group membership, who-talks-to-whom). Compare it directly with RVNT, which is E2EE by default with a post-quantum handshake and no central server: RVNT vs WhatsApp.