NIST SP800-38C.pdf

This Recommendation specifies an algorithm, Counter with Cipher Block Chaining-Message Authentication Code [1], abbreviated CCM, that can provide assurance of the confidentiality and authenticity of data. CCM is based on an approved symmetric key block cipher algorithm whose block size is 128 bits, such as the Advanced Encryption Standard (AES) algorithm currently specified in Federal Information Processing Standard (FIPS) Pub. 197 [2]; thus, CCM cannot be used with the Triple Data Encryption Algorithm [3], whose block size is 64 bits. CCM can be considered a mode of operation of the block cipher algorithm.