End-to-End Encryption

End-to-end encryption (E2EE) encrypts data on the sender's device and decrypts only on the receiver's device. Servers relay encrypted data without holding decryption keys. LINE, WhatsApp, and Signal use E2EE.

Unlike standard TLS/SSL where servers decrypt and re-encrypt, E2EE protects data even if servers are compromised. QR code images shared via E2EE apps are encrypted in transit, and some secure QR payment systems apply E2EE to transaction data.