AEADsalausmenetelmää

AEADsalausmenetelmä stands for Authenticated Encryption with Associated Data. It is a symmetric encryption mode that not only encrypts data but also provides authentication for both the encrypted data and unencrypted associated data. This means it ensures that the ciphertext has not been tampered with and that the associated data, which might be metadata like a packet header, is also authentic.

The primary benefit of AEAD is its ability to combine confidentiality and integrity in a single operation. Traditional encryption schemes often require separate mechanisms for encryption and message authentication, which can be complex to implement correctly and prone to errors. AEAD simplifies this by offering a unified solution.

Common AEAD algorithms include AES-GCM (Galois/Counter Mode) and ChaCha20-Poly1305. AES-GCM is widely used and is a standard in many network protocols like TLS. ChaCha20-Poly1305 is known for its performance, especially on platforms without dedicated AES hardware acceleration.

When using an AEAD scheme, a secret key is provided along with plaintext data and optional associated data. The algorithm produces a ciphertext and an authentication tag. To decrypt, the recipient uses the same key, the ciphertext, and the associated data to verify the authentication tag. If the tag is valid, the plaintext is recovered, and it is assured that neither the ciphertext nor the associated data has been altered. If the tag is invalid, decryption fails, indicating a potential security breach or transmission error.