End-to-end encryption

End-to-end encryption (E2EE) ensures only the sender and the final recipient hold the cryptographic keys to decrypt a message.

This is the gold standard for digital privacy: E2EE guarantees that no third party—not the service provider, ISP, or malicious actor—can access the plaintext data. The process relies on asymmetric cryptography: your device encrypts the message using the recipient's public key, and only their corresponding private key can unlock it. The server handles only ciphertext (unreadable data), eliminating the man-in-the-middle risk from the platform itself. Major platforms like Signal and WhatsApp use E2EE, with WhatsApp alone securing over 3 billion user conversations, proving its scalability and security profile.

https://en.wikipedia.org/wiki/End-to-end_encryption