Digital image recording for court-related purposes

While the evidentiary value of photographs submitted with original film material (ordinarily a negative or slide) has rarely been contested in the past, it is likely that the susceptibility of digital images to manipulation will lead to increasing doubt with respect to the authenticity of photographic images in the era of digital data processing. Faced with this situation, it is essential that all concerned, and law-enforcement agencies in particular, engage in concerted world-wide efforts to preserve and restore the evidentiary value of photographic images. This article describes an approach to ensuring the integrity and authenticity of photographic images during the image-recording phase currently favoured by the Bundeskriminalamt. Because the retroactive detection of manipulations on the basis of image content alone is likely to prove quite difficult, this concept presently shows the most promise. Reflections regarding the basic configuration of a manipulation-proof digital camera capable of meeting the stringent integrity and authenticity requirements imposed for images presented as evidence in court are discussed. We propose the use of a suitable digital signature, a method that is also used in other cases for the purpose of establishing the binding legal character of a digital expression of intent, as an effective means of protecting digital images against manipulation. Features built into the camera make it relatively easy to record additional characteristic parameters of the image-production process.