The periodic table of atomic controls [updated]
Many information security controls are multi-purpose, hence they could be specified in several places, several policies plus procedures and standards and guidelines etc. That multiplicity creates a nightmare for the ISO/IEC JTC 1/SC 27 project team trying to generate a succinct version of ISO/IEC 27002 without duplications, gaps or discrepancies in the control catalog. It’s also a potential nightmare for anyone writing corporate policies, or an opportunity depending on how you deal with it.
My current pragmatic approach is to mention [hopefully] all the important controls in each topic-specific policy template, with a reference section that mentions other related policies, creating a kind of policy matrix. I’m still wary of gaps and discrepancies though: with 60+ policies in our matrix so far, it’s fast approaching the limit of my intellectual abilities and memory to keep them all aligned! It’s an ongoing task to review and revise/update the policy templates, without breaking links, creating discrepancies, or missing anything important.
My mention of ‘control catalog’ hints at a more rigorous approach: a database where every control is listed once, definitively, and then referenced from all the places that need to describe or mandate or recommend the controls. That in turn requires us to be crystal-clear about what constitutes a control. User authentication, for instance, is in fact a complex of several controls such as identification, challenge-response, cryptography, biometrics, enrolment, awareness, logging, compliance, passwords/PINs and more. Some of those are themselves complex controls that could be broken down further … leading to the ultimate level of ‘atomic controls’ or ‘control elements’. The control catalog, then, would be built around a kind of periodic table of all known atomic information security controls, which can be used individually or assembled into 'compound controls' mitigating various information risks.
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UPDATE June 20: I published this blog item on LinkeDin to reach a wider spectrum of readers. Michala Liavaag kindly pointed out that NIST SP800-53 has a controls catalog ... but the controls listed in Appendix F are compound or complex controls, not elemental. I'm proposing to take the analysis down to the lowest level, to the building blocks from which practical controls are assembled.UPDATE June 27: in an opinion piece in CSO Magazine asserting that ROI is the wrong metric for cybersecurity, Rick Howard says:
"The idea of first principles has been around since the early Greek philosopher days. To paraphrase Aristotle, first principles in a designated problem space are atomic. They cannot be broken down any further. They are the building blocks for everything else. They drive every decision you make."