Encyclopedia of Cryptography and Security

2005 Edition
| Editors: Henk C. A. van Tilborg

Data Remanence

  • Markus Kuhn
Reference work entry
DOI: https://doi.org/10.1007/0-387-23483-7_95
Data remanence is the ability of computer memory to retain previously stored information beyond its intended lifetime. With many data storage techniques, information can be recovered using specialized techniques and equipment even after it has been overwritten. Examples:
  • Write heads used on exchangeable media (e.g., floppy disks, magstripe cards) differ slightly in position and width due to manufacturing tolerances. As a result, one writer might not overwrite the entire area on a medium that had previously been written to by a different device. Normal read heads will only give access to the most recently written data, but special high-resolution read techniques (e.g., magnetic-force microscopy) can give access to older data that remains visible near the track edges.

  • Even with a perfectly positioned write head, the hysteresis properties of ferromagnetic media can result in a weak form of previous data to remain recognizable in overwritten areas. This allows the partial recovery of...

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    A guide to understanding data remanence in automated information systems. National Computer Security Center, NCSC-TG-025, United States Department of Defense, September 1991.Google Scholar
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    Gutmann, Peter (2001). “Data remanence in semiconductor devices.” Proceedings of the 10th USENIX Security Symposium, Washington, DC, USA, 13–17.Google Scholar
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    Gutmann, Peter (1996). “Secure deletion of data from magnetic and solid-state memory.” Sixth USENIX Security Symposium Proceedings, San Jose, CA, 77–89.Google Scholar
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    Skorobogatov, Sergei (2002). “Low temperature data remanence in static RAM.” Technical Report UCAM-CL-TR-536, University of Cambridge, Computer Laboratory.Google Scholar

Copyright information

© International Federation for Information Processing 2005

Authors and Affiliations

  • Markus Kuhn

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