In May 2021, NIST initiated a review process for several publications, including the Special Publication (SP) 800-38A, Recommendation for Block Cipher Modes of Operation: Methods and Techniques and its addendum, Three Variants of Ciphertext Stealing for CBC Mode.
In response to the public comments received, NIST proposes to revise SP 800-38A to:
change the technical content as described below, and
convert (i.e., merge) SP 800-38A Addendum into the revised SP 800-38A.
Public comments on this proposal may be submitted to cryptopubreviewboard [at] nist.gov (subject: Comments%20on%20SP%20800-22%20Rev.%201a%20Decision%20Proposal) by April 22, 2022. Please use “Comments on SP 800-38A Decision Proposal” in the Subject.
More information about the review process is available at NIST's Crypto Publication Review Project.
Rationale for the Revision of SP 800-38A
SP 800-38A specifies five confidentiality modes of operation for block ciphers: Electronic Codebook (ECB), Cipher Block Chaining (CBC), Cipher Feedback (CFB), Output Feedback (OFB), and Counter (CTR).
The ECB mode encrypts plaintext blocks independently, without randomization; therefore, the inspection of any two ciphertext blocks reveals whether or not the corresponding plaintext blocks are equal. In the NIST National Vulnerability Database (NVD), the use of ECB to encrypt confidential information constitutes a severe security vulnerability; for example, see announcement proposal revise special publication
