Authorization of a file on a computer is provided for using a cryptographic hash of the file or other identifier to find one or more content ratings. Content ratings, coupled with source and publisher ratings, are used to evaluate the file against an authorization policy set up by a user, manufacturer, or corporate IT department. Files which are suspect due to low ratings are not authorized to run on the computer. Files for which little information can be found are left to the user to decide whether to authorize. Rating services provide aggregated content ratings based on editorial or user reviews, and index their searchable ratings based on cryptographic hashes of the files being evaluated. Rating services provide allow lists and exclude lists or may provide individual responses to queries containing cryptographic hashes of files.