The risks of conventional digital archives
Conventional procedures of digital preservation entail risks which may cause immense damage even for financially strong companies. Technological change leads to increases in productivity, but it also implies problems with the compatibility of devices.
The recurring migration of digital data appears to be the only solution. However, this is only the case if it can be assumed that the necessary financial resources are permanently available.
Another risk lies in the obsolescence of media and formats: certain media or their specific reading devices disappear over time, which leads to the fact that their data formats are no longer interpretable.
Requirements for secure long-term archiving
Against that background, the following security criteria for long-term archiving should be taken into consideration:
- Nowadays information should be stored in such a way that it can be easily found and interpreted in the future.
- Easy access, independent of technology, has to be guaranteed.
- The costs and their calculations have to be minimised throughout the life cycle of a record.
Microfilm as a stable medium for long-term archiving
Generally, there are two strategies in order to preserve information permanently:
Strategy 1: Automatic and continuous migration
Digital archives depend on a periodical migration of their data fonds, during which they are aligned with currently used media and formats. This strategy is suitable only to a limited extent, as its progression depends on ever new financial resources.
Strategy 2: Use of stable media to avoid migration
Instead of the continuous migration there is the option to defer migration as long as possible by using a stable optical medium, for example the Ilfochrome® Micrographic film that lasts 500 years,
ancient clay or stone tablets, or parchment.