Abstract: Systems and methods are disclosed that enable authentication based on a physical document. Specifically, a document authentication service is disclosed that utilizes characteristics of a physical document, such as an identification card already in a user's possession, to authenticate a user. In one embodiment, the characteristics of a document may be processed based at least in part on an expected wear of the document (e.g., from use by the user). Expected wear may be identified, for example, based on historical data gathered across a number of users of the document authentication service.