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

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.