Nonce-Based Symmetric Encryption

Symmetric encryption schemes are usually formalized so as to make the encryption operation a probabilistic or state-dependent function E of the message M and the key K: the user supplies M and K and the encryption process does the rest, flipping coins or modifying internal state in order to produce a ciphertext C. Here we investigate an alternative syntax for an encryption scheme, where the encryption process E is a deterministic function that surfaces an initialization vector (IV). The user supplies a message M, key K, and initialization vector N, getting back the (one and only) associated ciphertext C = EN K (M). We concentrate on the case where the IV is guaranteed to be a nonce—something that takes on a new value with every message one encrypts. We explore definitions, constructions, and properties for nonce-based encryption. Symmetric encryption with a surfaced IV more directly captures real-word constructions like CBC mode, and encryption schemes constructed to be secure unde...

• Type: Conference
• Year: 2004
• Where: FSE
• Authors: Phillip Rogaway
• Keywords: Cryptography, Encryption, Encryption Schemes, FSE 2004, Symmetric Encryption