A method, system and computer program product for controlling access to data files stored in a repository is disclosed. The invention entails a determination of the requested file's availability and the authorization and authentication of the requester. A requester may specify the format in which they wish to receive the data file, and facilities are provided for translating the requested file to the requested format if the file is not stored in the requested format. Advantageously, the invention provides a repository for retaining responses to requests so as to minimize successive requests against the repository for the same data file. Moreover, in such instances wherein a requested data file requires a format translation, a facility is provided for determining the correct stored file format to use as the input for the format translation. Such a determination may be based upon criteria such as minimizing data lost as a result of the translation or minimizing processing required in performing the translation.