An Abstract Machine Approach to Preserving Digital Information

Preserving digital information for a very long time is difficult even when using a durable passive storage medium such as photographic film stored under the right conditions. On film one can combine analog descriptions, that is, visual and thus human-readable text and diagrams, with encoded digital information. After hundreds of years, however, the formats used to represent and encode this information may have been forgotten, and any surviving source code may not simply be compiled and run. Explaining how to interpret data stored in a complex format runs the risks both of errors made today and of future misunderstandings. We present a solution based on (1) a very simple abstract machine, (2) independent, technology-neutral descriptions of the machine, preserved in analog form and aimed at future programmers and mathematicians, and (3) a C compiler targeting this machine. Currently, our toolset supports storing and retrieving data in the formats JPEG, TIFF and PDF/A, but other formats can be easily be added by adapting existing C programs for processing these formats. Binaries for the abstract machine are preserved alongside the digital information and the machine descriptions so that future generations can decode and present the information simply by implementing this machine.