AS 2805.5.2-2009 pdf download.Electronic funds transfer – Requirements for interfaces – Part5.2: Ciphers – Modes of operation for an n-bit block cipher.
AS 2805.5.2 establishes five mo(les of operation for applicatioais of au —l)it block cipher (e.g. protection of data trausuinssion, data storage). The defined uiiodes only provide protection of data confidentiality. Protection of data integrity and reqiurenients for pad(liflg the (lata are iiot within the scope of this International Standard. Also most modes do not protect the confident i al I ty of message len gt h information.
AS 2805.5.2 specifies the modes of operation and gives recommendations for choosing values of parameters (as appropriate).
The niodes of operation spified in this International Standard have beeui assiguied object ideui— tifiers iii accordance with ISO/IEC 9834. TIme list of assigne(l Ol)jCCt i(lentifwrs is given in Annex
A. In applications in which object identifiers are used, the object identifiers specified in Annex A are to be use(1 in preference to any other object i(Ientifiers that. niay exist for the imiode concerned.
NOTE Annex B (informative) contains comments on the properties of each mode. Block ciphers are specified in ISO/IEC 18033-3.
5 Requirements
For sonic of the described modes, padding of the plamtext variables may be reqiured.
For the Cipher Block Chaining (CBC) mode of operation (see clause 7), one parameter in needs to be selected. For the Cipher Feedback (CFB) mode of operation (see clause 8), three parameters r,j and k need to be selected. For the Output Feedback (OFB) iiiode of operation (see clause 9) and the Counter (CTR) mode of operation (see clause 10), one parameter j needs to be selected. Wlieii one of these iiiodes of operation is used the same paranieter value(s) need to be chosen and used by all communicating parties. These parameters need not be kept secret.