15.3 Security of generic composition In their seminal publication Authenticated Encryption: Relations among Notions and Analysis of the Generic Composition Paradigm , Bellare and Namprempre analyze
15.4.1 Authenticated encryption with associated data In this section, by associated data we mean any data that should be authenticated but not encrypted. There are some scenarios where it is useful
15.4.2 Avoiding predictability with nonces Recall that an encryption scheme is called probabilistic if it returns different ciphertexts when the same plaintext is repeatedly encrypted. Otherwise, an
15.5.1 Authenticated encryption with CCM To apply CCM, sender Alice must provide the following four inputs: How to perform authenticated encryption with CCM based on these four inputs is illustrated
15.5.2 Authenticated decryption with CCM To decrypt and authenticate Alice’s message using CCM, Bob must provide the following four inputs: In the first step, Bob computes the key stream Si =
16.1 Preliminaries According to the American security researchers David McGrew and John Viega, ”the Galois/Counter Mode is a block cipher mode of operation that uses universal hashing over a binary
The primary purpose of the initialization vector IV is to act as a nonce. As a result, it must be distinct for every authenticated encryption operation under the same key. As long as distinctiveness
16.1.2 GHASH function GCM’s authentication mechanism is based on a hash function called GHASH. The function contains a multiplication by a fixed parameter H within GCM’s 𝔽2128 field.
Analyzing the TLS record, Exams of IT, GHASH function, IT Certification, Security of generic composition
16.2 GCM security GCM’s biggest security risk is its fragility in case of nonce repetition. NIST’s GCM standard requires the following: The probability that the authenticated encryption function
16.3 GCM performance There is an old saying among cryptographers that the real challenge is not to design a secure algorithm, but one that is secure and fast. While this is typically said somewhat