Conquer the 2025 CISSP Challenge – Master Your InfoSec Skills with Confidence!

Rivest Cipher 6, also known as RC6, distinguishes itself from its predecessor, RC5, by being one of the finalists in the Advanced Encryption Standard (AES) competition held by the National Institute of Standards and Technology (NIST). This competition was conducted to determine a new federal standard for encryption, and although RC6 ultimately did not win, its recognition as a finalist speaks to its design and performance merits in the realm of cryptographic algorithms.

RC6 incorporates notable features such as the use of a block size of 128 bits, a variable key size (ranging from 128 to 256 bits), and a significantly improved structure derived from its predecessor to enhance security and performance. This recognition as an AES finalist is a key distinction, as it associates RC6 with a set of standards that aim for robustness against various cryptographic attacks, which was a critical consideration during the AES competition.

The other options do not accurately reflect the fundamental characteristics of RC6. For example, RC6 is not solely a public key cipher; it operates in the domain of symmetric key encryption. Additionally, it is not described as an asymmetric circuit, which refers to entirely different cryptographic concepts. Finally, stating that it requires no keys for encryption contradicts