Certified Information Systems Security Professional (CISSP) Practice Exam

The abbreviation CBC stands for Cipher Block Chaining, which is a mode of operation for block ciphers. In this method of encryption, each block of plaintext is combined with the previous ciphertext block before being encrypted. This chaining process adds randomness and security to the encrypted output, as it ensures that the same plaintext block will not always encrypt to the same ciphertext block, depending on its position in the sequence.

This approach enhances the security of the encryption process by preventing patterns in the plaintext from being directly observed in the ciphertext. CBC mode requires an initialization vector (IV) to ensure that each encryption operation produces a unique result, even when the same plaintext is encrypted multiple times.

Other options, such as Cipher Binary Coding, Computer Block Chaining, and Combined Block Cipher, do not accurately define the established term or its mechanism in cryptographic contexts. They misrepresent concepts related to block ciphers or do not exist as recognized modes of operation. Understanding the significance of CBC in cryptography is crucial for implementing secure encryption practices.