Digital objects or entities present us with particular problems of an acute nature. The most acute of these are the issues surrounding what constitutes identity within the digital world and between digital entities. These are problems that are important in many contexts but, when dealing with digital texts, documents, and certification, an understanding of them becomes vital legally, philosophically, and historically. Legally, the central issues are those of authorship, authenticity, and ownership; philosophically, we must be concerned with the sorts of logical relations that hold between objects and in determining the ontological nature of the object; and historically, our concern centers around our interest in chronology and the recording of progress, adaptation, change, and provenance. Our purpose is to emphasize why questions of digital identity matter and how we might address and respond to some of them. We will begin by examining the lines along which we draw a distinction between the digital and the physical context and how, by importing notions of transitivity and symmetry from the domain of mathematical logic, we might attempt to provide at least interim resolutions of these questions.