ISO/IEC 27004:2009 Information technology — Security techniques ― Information security management - Measurement
Scope and purpose
ISO/IEC 27004 covers information security management measurements, generally known as ‘security metrics’.
The standard is intended to help organizations measure, report on and hence systematically improve the effectiveness of their Information Security Management Systems.
It “provides guidance on the development and use of measures and measurement in order to assess the effectiveness of an implemented information security management system (ISMS) and controls or groups of controls, as specified in ISO/IEC 27001. This would include policy, information security risk management, control objectives, controls, processes and procedures, and support the process of its revision, helping to determine whether any of the ISMS processes or controls need to be changed or improved.”
The following sections are key:
Information security measurement overview;
Measures and measurement development;
Data analysis and measurement results reporting;
Information Security Measurement Program evaluation and improvement.
Annex A suggests a template on which to describe a metric, while Annex B offers some worked examples.
The standard is quite detailed in terms of the mechanics of measurement processes. It laboriously describes how to collect “base measures”, use aggregation and mathematical calculations to generate “derived measures”, and then apply analytical techniques and decision criteria to create “indicators” used for ISMS management purposes. Unfortunately, it does not offer much guidance on which base measures, derived measures or indicators might actually be worth all this effort in terms of managing information security.
Status of the standard
Although ISO/IEC JTC1/SC27 recognizes that metrics are an essential tool for managing an ISMS, the project that initially developed the standard had long and troubled history. Hundreds of pages of comments from the national bodies were received even at the late FCD stage, few of which were resolved prior to publication: since guidance on security metrics was sorely needed, the standard was deemed ‘good enough’ to publish rather than delaying it still further.
The standard was first published in 2009 and is available for CHF162 from the ISO/IEC webstore.
ISO/IEC 27004 is now being revised. Contributions have been invited from national bodies. We sincerely hope that a far more usable and practical standard will emerge in a few years.
Meanwhile, for those who simply can’t wait, we’ve launched a separate website on information security metrics outlining the innovative PRAGMATIC approach which, we believe, addresses many of the shortcomings of 27004 - for example, how to select worthwhile metrics. See what you think!