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authenticated encryption

Encryption that also notices if the scrambled data was changed.

Authenticated encryption (AES-GCM, ChaCha20-Poly1305) gives confidentiality and integrity under one shared key, provided a nonce is never reused with the same key.

Examples

  • AES-GCM encrypts a reading and also detects if anyone changed the ciphertext on the way.

  • Reusing a nonce with the same AES-GCM key breaks both its secrecy and its tamper detection.

See also

message authentication code key agreement hash function
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