U.S. flag   An official website of the United States government
Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.


Secure .gov websites use HTTPS
A lock (Dot gov) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Block Cipher Techniques

Block Cipher Modes

A block cipher mode, or mode, for short, is an algorithm that features the use of a symmetric key block cipher algorithm to provide an information service, such as confidentiality or authentication.

Currently, NIST has approved fourteen modes of the approved block ciphers in a series of special publications. As summarized on the Current Modes page, there are eight confidentiality modes (ECB, CBC, OFB, CFB, CTR, XTS-AES, FF1, and FF3), one authentication mode (CMAC), and five combined modes for confidentiality and authentication (CCM, GCM, KW, KWP, and TKW).

Several other modes have been submitted to NIST for consideration; the submission documents are available at the Modes Development page. NIST welcomes public input on whether to approve any of these modes. Comments may be submitted to EncryptionModes@nist.gov.

Created January 04, 2017, Updated September 05, 2023