Certified Information Systems Security Professional (CISSP) Practice Exam

The primary function of the Chaining technique in cryptography is to seed the previous encrypted block into the next block to be encrypted. This process, known as "block chaining," is essential in certain modes of operation used in block ciphers, such as Cipher Block Chaining (CBC) mode.

In CBC mode, each plaintext block is XORed with the previous ciphertext block before being encrypted, effectively linking the blocks together. This chaining mechanism means that identical plaintext blocks will produce different ciphertext outputs depending on their position in the sequence, enhancing the security against certain types of attacks, such as pattern recognition and replay attacks.

The chaining also contributes to the randomness and unpredictability of the ciphertext, as even small changes in the plaintext or in one of the previous ciphertext blocks can result in significantly different outputs. This characteristic is crucial for maintaining data confidentiality and integrity in cryptographic systems.