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4.2.2.3 Modes of Operation

NIST platform security: roots of trust, firmware and secure enclaves SP 800-57 Part 1 Rev. 4
All changes in this version
first version loaded 4 Cryptographic Algorithms part of 4.2.2

Title

Modes of Operation

Control

With a block-cipher encryption operation, the same plaintext block will always encrypt to the same ciphertext block whenever the same key is used. If the multiple blocks in a typical message are encrypted separately, an adversary can easily substitute individual blocks, possibly without detection. Furthermore, certain kinds of data patterns in the plaintext, such as repeated blocks, are apparent in the ciphertext. Cryptographic modes of operation have been defined to alleviate this problem by combining the basic cryptographic algorithm with variable initialization vectors and some sort of feedback of the information derived from the cryptographic operation (see the [SP800-38] series of publications). The NIST Recommendation for Block Cipher Modes of Operation [SP800-38A] defines modes of operation for the encryption and decryption of data using block cipher algorithms, such as AES and TDEA. Other modes approved for encryption are specified in other parts of [SP800-38]; some of these modes also produce message authentication codes (see Section 4.2.3 ). Guidance on the secure use of each mode is provided for each mode, in addition to the mode specification. Note that one of the modes included in [SP800-38A] is the Electronic Codebook (ECB) mode. This mode is not recommended for general use, as the ciphertext leaks information about plaintext after relatively small amounts of structured data is encrypted.