Sketchifying and the Instagram of Security Design

About a year ago, when I received the review comments on Point-and-Shoot Security Design (discussed in this blog before), I was confronted with a question I could not answer at that time. One reviewer took my photography analogy seriously and asked:

What ist the Instagram of information security?

Tough one, the more so as I never used Instagram. But the question starts making sense in the light of an explanation that I came across recently:

»Ask any teenager if they would want to share multi-photo albums on Instagram, and they wouldn’t understand you. The special thing about Instagram is that they focus on one photo at a time. Every single photo is a piece of handcrafted excellence. When you view an Instagram photo, you know the photo is the best photo of many photos. The user chose to upload that specific photo and spent a good amount of time picking a filter and editing it.«

(The Starbucks Theory — Thoughts on creativity)

One of the points I made in my paper was that design requires design space exploration before refinement and caring about details. Even if one starts to consider security early in a development process, one may still end up bolting security on rather than designing it in if one lets non-security requirements drive the design process and simply looks for security mechanisms to add to the design. One should rather, I theorized, actively search the security design space for solution candidates and evaluate them against threat models to identify viable solutions to the security problems an operational environment will be posing. Designing a secure system is not in the first place about defining a security policy or guaranteeing certain formal, microscopic security properties. Security design is rather about shaping the behavior of adversarial actors such that the resulting incident profile becomes predictable and acceptable.

Today I came across an article by Željko Obrenović, whose work I was unaware of at the time of writing the point-and-shoot paper. In his article Software Sketchifying: Bringing Innovation into Software Development (IEEE Software 30:3 May/June 2013) he outlines the ideas behind Sketchlet, a tool to help nonengineers to try out different interaction designs. I haven’t tried Sketchlet yet, but apparently it allows interaction designers to work with technological components and services, combining and arranging them through a direct manipulation user interface. Without having to program, the designer can take building blocks and play with them to try out ideas. Designers can thus quickly discard bad ideas before taking a selection of apparently good ones into the prototyping and later, the implementation stage.

Conceptually this is pretty close to what I’d like to see for security design. There’s a catch, however: security design deals with dimensions that can’t be experienced immediately, needs to be visualized through evaluation and analysis. Design sketches need to be evaluated in a second dimension against threat models capturing and representing adversary behavior. Nevertheless, Sketchifying looks like an interesting starting point for further exploration.


About Sven Türpe

Sven Türpe is a computer scientist. His current research focus is on security engineering methods, techniques, and tools. All opinions expressed in this blog are his own.