Keeping Tabs on WhatsApp's Encryption | c't Magazin

the core problem with WhatsApp's end-to-end encryption: You never really know if it is actually being used.

Neither when sending nor when receiving messages with the official WhatsApp client is there any indication if E2E encryption is in place. Our lab tests only show that messages are encrypted in principle but that is not enough for dependable use in the real world. Even heavier weighs the fact that, as far as we know, WhatsApp has never committed to guarantee its users E2E encryption. E2E encryption with WhatsApp therefore remains a token effort.