Editing Triple DES (section)

==Encryption of more than one block==
As with all block ciphers, encryption and decryption of multiple blocks of data may be performed using a variety of [[modes of operation]], which can generally be defined independently of the block cipher algorithm. However, ANS X9.52 specifies directly, and NIST SP 800-67 specifies via SP 800-38A,<ref>[http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf NIST Special Publication 800-38A, ''Recommendation for Block Cipher Modes of Operation, Methods and Techniques'', 2001 Edition] (PDF)</ref> that some modes shall only be used with certain constraints on them that do not necessarily apply to general specifications of those modes. For example, ANS X9.52 specifies that for [[cipher block chaining]], the [[initialization vector]] shall be different each time, whereas ISO/IEC 10116<ref>{{cite web
| url=https://www.iso.org/standard/38761.html
| title=ISO/IEC 10116:2006 Information technology -- Security techniques -- Modes of operation for an n-bit block cipher
| edition=3
| date=February 2006
| access-date=2017-09-05}}</ref> does not. FIPS PUB 46-3 and ISO/IEC 18033-3 define only the single-block algorithm, and do not place any restrictions on the modes of operation for multiple blocks.