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8 Jan 2014 : Digital Forensics: can it really be an academic discipline? #
Although Digital Forensics isn't my main research area, it is one that I've had involvement with for some time. I work with many very talented researchers in the area of digital forensics, and have worked in the past with the Police in testing new digital forensics tools.

Yet in spite of this, I've struggled with the underpinnings of digital forensics for some time. Unlike security research, which is built on a set of clear principals that remain consistent over time, the principal techniques of digital forensics appear to me to be inevitably temporary and fleeting.

To be clear, I do understand that there are clearly defined goals for good digital forensics practice, and that the overarching aim is to collect evidence within the constraints of these requirements. For example, the need to collect data in a non-destructive way, while ensuring traceability, collecting information about provenance, and ideally supporting repeatability of collection. If digital forensics constrained itself to the pure pursuit of managing data based on these principals, then that would provide scope for a practically useful, but theoretically unremarkable area for future research.

I also understand that there are interesting questions related to how data can be analysed and interpreted to better understand it . But to me this falls under intelligence gathering rather than digital forensics. It fits into a much broader class of research (data analysis) which exists separately and independently.

Instead, at the heart of most digital forensics research you'll invariably find a data collection technique that's designed to uncover unexpected data. Data that the user never intended to persist or become accessible. As others have noted, this goal is diametrically opposed to the central goal of security, which is to offer a strict decision over what access is granted and to whom (where access can apply to not just data but also actions). Presumably, a tightly configured and accurately implemented security policy would prevent any effective digital forensics techniques from being used.

As a consequence, much digital forensics research focusses on bypassing security measures, making use of unanticipated data leaks or amalgamating data that had hitherto been considered benign. As soon as these techniques have been identified, a good security process should provide a countermeasure.

Certainly this offers a lucrative seam of challenges to undertake research around. However, each is just the exploitation of a transient mistake, framed from a perspective of intent. Consequently, when I read about digital forensics research I always struggle to understand the enduring principals which have been uncovered by it.

In contrast, the enduring principals of security research are clear. The aim there is to provide control: the ability to allow or disallow access to digital functionality or information based on a stated security policy. The security policy might change, and so the controls and feedback given to the user might also change, but good security research accommodates this without diverging from this clearly defined goal.

No doubt security doesn't always work like this and there are many challenges to achieving it. Security policies must be suitably complete, definable and understood by the user to achieve the intended results. There must be methods for applying the policy which ensure that the model (policy) and design (controls) align. Finally, the implementation must be correct, so that it - ideally verifiably - matches the requirements.

There will always be difficulties that arise in achieving this, but there is no reason why the methods developed today, which fulfil these objectives within a particular context, shouldn't be as applicable in the future as they are now. I'll grant that the completeness part may be an unachievable aspiration. But this doesn't make the steps towards it any less valid.

On the other hand, the goal of digital forensics is always moving: not forwards but sideways. So what are the underlying principals of digital forensics that an academic research discipline can uncover? How will digital forensics survive as a research area in the future, other than through the drive for practical outcomes? What area is there left for digital forensics to inhabit, once the security problem has been solved?

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