A critical distinction between printed and electronic publications is the ease with which their integrity can be determined. The Task Force on Archiving of Digital Information defined five components that constitute the integrity of digital documents: content (intellectual substance contained in information objects), fixity (content fixed in a discrete object as opposed to continuously updated documents), reference (reliable systems for locating and citing), provenance (a record of the document's origin and chain of custody), and context (a document's interaction with elements in the wider digital environment) (Garrett and Waters, 1996). Printed publications do not create doubt about their integrity; we take for granted that they have not been changed since they were published. Electronic publications, in contrast, can be changed in various ways: accidentally (for instance during copying to newer devices); on purpose, with well-meant intention (as is the case with dynamic documents); or on purpose, without well-meant intention, i.e., through fraud (Graham, 1994). Mechanisms to prove the integrity of data and information systems are not only necessary in order to trace fraud, but also to make sure the documents have been moved to a new storage medium without loss.