Introduction: Opportunities and challenges for electronic evidence

Beyond the different and varied rules that each Member State adopts regard- ing the admissibility and development of evidence, including digital evidence, elements that in any case must be guaranteed are its relevance and its authenticity with respect to the case being examined. However, these requirements are far from easy to achieve, taking into account some peculiar characteristics of digital evidence, like, for example, its fragility (easily alterable, damageable and destructible) and its immateriality, namely the difficulty in associating particular evidence to a physical object: often it is confused with the device that contains it and therefore closely linked to the concepts of changeability and volatility. This means that the lifecycle of digital evidence must always be accompanied by documentation, always kept up to date, constituting the so-called chain of custody, i.e., the document that describes in detail what happens to digital evidence from the moment in which it was identified as evidence until its presentation before the judge in the trial phase, more specifically, the person who took possession of it to preserve its authenticity, when, where and how, and in what manner. The issue of digital evidence is necessarily interdisciplinary in that it affects different areas: the law in its national, European and international forms, digital forensics, computer science, sociology of law and diplomatics. The latter discipline, perhaps the least known among those mentioned, is focused on "studying the forms that official, legally probative or even constitutive documentation has taken over time.