A Mini-Architecture for Security Guidance
Benjamin Tomhave wrote about “tiering” security guidance when I cross-posted a comment to my last blog entry on the SC-L mailing list. Quoting him:
The higher up you are in the policy framework, the more general and time-enduring the content should be. The farther you progress down the framework to a more detailed level, the more perishable the content will be, out of necessity.
Later he continues:
…is because implementers need it. They’re not security experts (usually) and do not necessarily grok security the same way a seasoned (salty?) security person might.because “implementers need it”.
This tiering was implicit to my first post. In fact your most senior security resources can probably use nothing but Security Principals (as described by McGraw’s BSS Book and the famous Saltzer paper) and find both insidious vulnerabilities as well as brand-new “Game over” architectural flaws with new development technologies they aren’t familiar with. But, the more junior (inexperienced) or development-oriented (constructive) the person being targeted, the more specific the guidance must be in order to be valuable without requiring inordinate effort.
Because we’re trying to change the behavior of the majority of our Developers–who range in skill from OK to Hero and whom may have never had even a security awareness class–I find “technology-specific” guidance moves the ball the furthest.
In my previous two posts I talk about forms various levels of standards take, and the way in which one might create it. It occurs to me that I all but showed the bigger picture and might as well follow up to do so. Below, you’ll find a map of how I show security guidance flowing throw and effecting a software development team (click-through for full detail):
As information moves from top to bottom and from left to right it becomes more specific and actionable, but also more perishable (as has been said). To build security in, one must think about security’s implications throughout the lifecycle, so I see no reason why security knowledge (regardless of how specific) shouldn’t mirror artifacts used to construct the application itself: software requirements, design, and the code itself.
Though not central to this discussion, the diagram has been annotated to indicate who should produce and consume this information. Here, I’ll point out that your centralized Application Security Resources can probably most effectively and efficiently create the generic security guidance, but will need help of Security Architects to create the more technology-specific guidance and garner broad buy-in.
My last post presented a brief model of how one might organize and fund this in practice.
-jOHN
Technorati Tags: knowledge architecture, software security
