You are viewing this page in an unauthorized frame window. This is a potential security issue, you are being redirected to https://csrc.nist.gov . An official website of the United States government Here’s how you know Here’s how you know Official websites use .gov A .gov website belongs to an official government organization in the United States. Secure .gov websites use HTTPS A lock ( Lock Locked padlock icon ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. Search Search CSRC MENU Search Search Projects Publications Expand or Collapse Drafts for Public Comment All Public Drafts Final Pubs FIPS (standards) Special Publications (SP s ) IR (interagency/internal reports) CSWP (cybersecurity white papers) ITL Bulletins Project Descriptions Journal Articles Conference Papers Books Topics Expand or Collapse Security & Privacy Applications Technologies Sectors Laws & Regulations Activities & Products News & Updates Events Glossary About CSRC Expand or Collapse Computer Security Division Cryptographic Technology Software Security Group Hardware Security Group Security Engineering and Risk Management Applied Cybersecurity Division Cybersecurity and Privacy Applications National Cybersecurity Center of Excellence (NCCoE) National Initiative for Cybersecurity Education (NICE) Contact Us Information Technology Laboratory Computer Security Resource Center Publications NIST SP 800-38A Recommendation for Block Cipher Modes of Operation: Three Variants of Ciphertext Stealing for CBC Mode Share to Facebook Share to X Share to LinkedIn Share ia Email Documentation Topics Date Published: October 2010 Planning Note ( 04/28/2023 ): NIST is planning to convert this publication by merging it into a revised SP 800-38A. See the announcement for full details. Author(s) Morris Dworkin (NIST) Abstract A limitation to Cipher Block Chaining (CBC) mode, as specified in NIST Special Publication 800-38A, is that the plaintext input must consist of a sequence of blocks. Ciphertext stealing is a padding method in which the required padding bits are "stolen" from the penultimate ciphertext block. This addendum to SP 800-38A specifies three variants of CBC mode with ciphertext stealing. These variants, which differ only in the ordering of the ciphertext bits, can encrypt any input whose bit length is greater than or equal to the block size. Unlike conventional padding methods, these variants do not expand the length of the data. A limitation to Cipher Block Chaining (CBC) mode, as specified in NIST Special Publication 800-38A, is that the plaintext input must consist of a sequence of blocks. Ciphertext stealing is a padding method in which the required padding bits are "stolen" from the penultimate ciphertext block. This... See full abstract A limitation to Cipher Block Chaining (CBC) mode, as specified in NIST Special Publication 800-38A, is that the plaintext input must consist of a sequence of blocks. Ciphertext stealing is a padding method in which the required padding bits are "stolen" from the penultimate ciphertext block. This addendum to SP 800-38A specifies three variants of CBC mode with ciphertext stealing. These variants, which differ only in the ordering of the ciphertext bits, can encrypt any input whose bit length is greater than or equal to the block size. Unlike conventional padding methods, these variants do not expand the length of the data. Hide full abstract Keywords block cipher ; ciphertext stealing ; cryptography ; encryption ; mode of operation Control Families System and Communications Protection Documentation Publication: https://doi.org/10.6028/NIST.SP.800-38A-Add Download URL Supplemental Material: None available Publication Parts: SP 800-38A SP 800-38B SP 800-38C SP 800-38D SP 800-38E SP 800-38F SP 800-38G Document History: 10/21/10: SP 800-38A (Final) Topics Security and Privacy authentication , cryptography HEADQUARTERS 100 Bureau Drive Gaithersburg, MD 20899 X (link is external) facebook (link is external) linkedin (link is external) instagram (link is external) youtube (link is external) rss govdelivery (link is external) Want updates about CSRC and our publications? Subscribe Contact Us | Our Other Offices Send inquiries to [email protected] Site Privacy Accessibility Privacy Program Copyrights Vulnerability Disclosure No Fear Act Policy FOIA Environmental Policy Scientific Integrity Information Quality Standards Commerce.gov Science.gov USA.gov Vote.gov