Security of generic composition – Block Ciphers

Analyzing the TLS record, Exams of IT, GHASH function, IT Certification, Plaintext integrity, Security of generic composition, TLS Record protocol

CTR mode – Block Ciphers and Their Modes of Operation

08/31/202408/31/2024

Posted by Whitney Koehler

14.4.5 CTR mode The Counter (CTR) mode, illustrated in Figure 14.12, is a mode of operation that applies the underlying block cipher f to generate a key stream that is subsequently used for

Indistinguishability under a chosen-ciphertext attack 3 – Authenticated Encryption

01/20/202408/31/2024

Posted by Whitney Koehler

It is easy to show that even given a probabilistic public-key encryption scheme like the one defined above – that is, a scheme offering semantic security against any polynomial time adversary –

Authenticated encryption – generic composition – Authenticated Encryption

09/30/202308/31/2024

Posted by Whitney Koehler

15.2 Authenticated encryption – generic composition An authenticated encryption (AE) scheme is a symmetric-key encryption scheme that provides both confidentiality as well as message integrity and

Avoiding predictability with nonces – Authenticated Encryption

01/20/202308/31/2024

Posted by Whitney Koehler

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

Authenticated decryption with CCM – Authenticated Encryption

10/20/202208/31/2024

Posted by Whitney Koehler

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 =

GHASH function 2 – The Galois Counter Mode

06/07/202208/31/2024

Posted by Whitney Koehler

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

GCM security – The Galois Counter Mode

03/05/202208/31/2024

Posted by Whitney Koehler

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

GCM performance 2 – The Galois Counter Mode

11/30/202108/31/2024

Posted by Whitney Koehler

To make it simple for you to reproduce the results we’re about to show, we will again use the OpenSSL Docker image. It goes without saying that if you want to obtain performance results for a

TLS record payload protection – TLS Record Protocol Revisited

08/15/202108/31/2024

Posted by Whitney Koehler

17.3 TLS record payload protection As illustrated in Figure 17.1, before data is transmitted over the wire, the TLS record protection functions – denoted by E in Figure 17.1 – encrypt

Per-record nonce – TLS Record Protocol Revisited

07/20/202108/31/2024

Posted by Whitney Koehler

17.4 Per-record nonce Alice and Bob keep a 64-bit sequence number for reading and writing TLS records. They increment this number every time they read or write a TLS record. At the start of a TLS