Preface Standards development within the Information Technology sector is harmonized with international standards development. Through the CSA Technical Committee on Information Technology (TCIT), Canadians serve as the Canadian Advisory Committee (CAC) on ISO/IEC Joint Technical Committee 1 on Information Technology (ISO/IEC JTC1) for the Standards Council of Canada (SCC), the ISO member body for Canada and sponsor of the Canadian National Committee of the IEC. Also, as a member of the International Telecommunication Union (ITU), Canada participates in the International Telegraph and Telephone Consultative Committee (ITU-T). At the time of publication, ISO/IEC 9797-1:2011 is available from ISO and IEC in English only. CSA will publish the French version when it becomes available from ISO and IEC. Scope This part of ISO/IEC 9797 specifies six MAC algorithms that use a secret key and an n-bit block cipher to calculate an m-bit MAC. This part of ISO/IEC 9797 can be applied to the security services of any security architecture, process, or application. Key management mechanisms are outside the scope of this part of ISO/IEC 9797. This part of ISO/IEC 9797 specifies object identifiers that can be used to identify each mechanism in accordance with ISO/IEC 8825-1. Numerical examples and a security analysis of each of the six specified algorithms are provided, and the relationship of this part of ISO/IEC 9797 to previous standards is explained.