Reliability of Digital Evidence

Digital investigators do not currently have a systematic method for stating the certainty they are placing in the digital evidence they are using to reach their conclusions. This lack of formalization makes it more difficult for courts and other decision makers to assess the reliability of digital evidence and the strength of digital investigators' conclusions. The Certainty Scale presented in Chapter 7 provides a consistent method of referring to the relative certainty of different types of digital evidence. The immediate aim of the Certainty Scale is to improve our ability to assess the reliability of digital evidence.

Ultimately, it is hoped that this Certainty Scale will point to areas that require additional attention in digital evidence research. Debate over C-values in specific cases may reveal that certain types of evidence are less reliable than was initially assumed. For some types of digital evidence, it may be possible to identify the main sources of error or uncertainty and develop analysis techniques for evaluating or reducing these influences. For other types of digital evidence, it may be possible to identify all potential sources of error or uncertainty and develop a more formal model for calculating the level of certainty for this type of evidence.