ISO/IEC 10116 Information technology — Security techniques — Modes of operation for an n-bit block cipher is an international standard that specifies modes of operation for block ciphers of any length.
The modes defined are:
- Electronic codebook (ECB)
- Cipher block chaining (CBC)
- Cipher feedback (CFB)
- Output feedback (OFB)
- Counter (CTR)
The standard notes that some modes require padding, but states that "Padding techniques ... are not within the scope of this International Standard."
- ISO/IEC 10116:2006 Information technology — Security techniques — Modes of operation for an n-bit block cipher
- ISO-IEC 10116:2006, clause 5, Requirements