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Recommendation for Block Cipher Modes of Operation: Methods for Key Wrapping



Morris J. Dworkin


This publication describes cryptographic methods that are approved for "key wrapping," i.e., the protection of the confidentiality and integrity of cryptographic keys. In addition to describing existing methods, this publication specifies two new, deterministic authenticated-encryption modes of operation of the Advanced Encryption Standard (AES) algorithm: the AES Key Wrap (KW) mode and the AES Key Wrap With Padding (KWP) mode. An analogous mode with the Triple Data Encryption Algorithm (TDEA) as the underlying block cipher, called TKW, is also specified, to support legacy applications.
Special Publication (NIST SP) - 800-38F
Report Number


authenticated encryption, authentication, block cipher, computer security, confidentiality, cryptography, encryption, information security, key wrapping, mode of operation


Dworkin, M. (2012), Recommendation for Block Cipher Modes of Operation: Methods for Key Wrapping, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed June 17, 2024)


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Created December 13, 2012, Updated November 10, 2018