Applying digital stratigraphy to the problem of recycled storage media

Abstract

Previous work has shown that second-hand or even new devices with recycled components can contain remnants of old data. Given a situation where incriminating evidence is found in non-allocated space of such a device, this presents an attribution problem. In archaeology or geology, stratigraphy studies the arrangement of strata, or layers, often used as a dating technique based on the premise that newer layers are situated above older layers. The digital stratigraphy technique applies the concept to digital forensics and considers how data is positioned and overlayed on disk to make inferences about when data was created. This research investigates the extent to which this technique could resolve the data provenance challenge associated with recycled digital storage media. This paper presents an automated file system activity simulation framework that allows creation, deletion and modification actions to be carried out at scale using specific file system drivers. Using this tool, a series of experiments are carried out to gain an understanding of file system driver behaviour and address this practical question of provenance of data in non-allocated space.