Ensuring Integrity and Authenticity for Images in Digital Long-Term Preservation

Digital long-term preservation has become an important topic not only in the preservation domain, but also due to facilitation by several national and international projects like US National Digital Information Infrastructure and Preservation Program [1], the German NESTOR project [2] and the EU FP7 SHAMAN Integrated Project [3]. The reason for this is that a large part of nowadays produced documents and other goods are digital in nature and even some - called "born-digital" - have no analog master. Thus a great part of our cultural and scientific heritage for the coming generations is digital and needs to be preserved as reliable as it is the case for physical objects even surviving hundreds of years. However, the continuously succession of new hardware and software generations coming in very short intervals compared to the mentioned time spans render digital objects from just some generations ago inaccessible. Thus they need to be migrated on new hardware and into newer formats. At the same time integrity and authenticity of the preserved information is of great importance and needs to be ensured. However this becomes a challenging task considering the long time spans and the necessary migrations which alter the digital object. Therefore in a previous work [4] we introduced a syntactic and semantic verification approach in combination with the Clark-Wilson security model [5]. In this paper we present a framework to ensure the security aspects of integrity and authenticity of digital objects especially images from the time of their submission to a digital long-term preservation system (ingest) up to its latter access and even past this. The framework especially describes how to detect if the digital object has retained both of its security aspects while at the same allowing changes made to it by migration.