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Draft Publication 800-38G
July 08, 2013

NIST is pleased to announce that Draft NIST Special Publication 800-38G, Recommendation for Block Cipher Modes of Operation: Methods for Format-Preserving Encryption, is available for public comment. Format-preserving encryption (FPE) has emerged as a useful cryptographic tool, whose applications include financial-information security, data sanitization, and transparent encryption of fields in legacy databases. 
Three methods are specified in this publication: FF1, FF2, and FF3. Each is a format-preserving, Feistel-based mode of operation of the AES block cipher. FF1 was submitted to NIST by Bellare, Rogaway and Spies under the name FFX[Radix]; FF2 was submitted to NIST by Vance under the name VAES3; and FF3 is the main component of the BPS mechanism that was submitted to NIST by Brier, Peyrin, and Stern. The submission documents are available at the Block Cipher Techniques - Modes Development page.

Comment period CLOSED on: September 3, 2013. Questions? Send email to:

Created December 22, 2016, Updated June 22, 2020