Deleting index entries from compliance storage
Soumyadeb Mitra, Marianne Winslett, Nikita Borisov · 2008
In response to regulatory focus on secure retention of electronic records, businesses are using magnetic disks configured as write-once read-many (WORM) compliance storage devices to store business documents such as electronic mail for their mandated retention periods. A document committed to a compliance storage device cannot be altered or deleted even by a superuser until its retention period is over, and hence is secure from attacks originating from company insiders. Secure retention, however, is only a part of a document's lifecycle: it is often crucial to properly delete documents once their retention period ends. It is relatively simple to delete a document, but much harder to remove its index entries from WORM. Yet if these entries are not obliterated, the contents of the deleted document can often be reconstructed.