Good morning, We use Toast442.org's MD5, http://www.toast442.org/, to run our checksums. It is free Windows software and works rather well from our perspective. We have used it for about 3 years. All checksums generated are kept in the folder containing the digital files and is named so that we know exactly what it is for. In our case, we give everything a batch number, so the checksum is saved using that particular batch code. Should the data in folder change, a very rare occurrence, the checksum would be run again. Miriam [log in to unmask] wrote: >How many of you employ checksum files to verify digital copies over time? What checksum level do you use and, what do you do with the checksum files, do you keep them with the digital copies, elsewhere, etc? > >Thank you. > > -- Miriam Meislik Archivist/ Photograph Curator Archives of Industrial Society University of Pittsburgh 7500 Thomas Blvd. Pittsburgh, PA 15260 (412)244-7075 voice (412)244-7077 fax [log in to unmask] http://www.library.pitt.edu/libraries/archives/archives.html http://digital.library.pitt.edu/pittsburgh http://images.library.pitt.edu/pghphotos Everyone has a photographic memory. Some just don't have film. --Steven Wright