Which block sizes are utilized by the symmetric block cipher RC5?

RC5 is a symmetric block cipher that was designed by Ron Rivest in 1994. One of its key characteristics is its flexibility regarding block size, which allows for varying key lengths and block lengths. The correct answer points to the block sizes of 32 bits, 64 bits, and 128 bits, which can be configured depending on the specific needs of the application.

RC5 is particularly known for its dynamic nature, as it allows the block size to be set to 32, 64, or 128 bits, making it adaptable for different security requirements and processing capabilities. This versatility helps accommodate various hardware and software systems that can benefit from optimized performance with different block sizes.

The incorrect options refer to block sizes that are not supported by RC5. For instance, while the absence of a 16-bit block size is evident in the cryptographic design of RC5, it does not utilize any configurations with 256-bit block size, which significantly exceeds the specifications set out in its design. Understanding these particular block sizes is essential for grasping the cipher's operational characteristics and applications in cryptographic security.