Patent · US Expired

Encryption of system paging file

US7325115B2 · kind B2 · utility

3Cited by
6References
19Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 25, 2003
Grant dateJan 29, 2008
Priority date
Expiry dateSep 22, 2025

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F2221/2143
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

An operating system copies data from memory pages into a paging file on disk, in order to free up space in the memory. A mechanism is disclosed that causes the data to be encrypted as it is copied into the paging file, thereby protecting the paged data from unauthorized (or otherwise undesired) observation. The data that is stored in the paging file is encrypted with a session key, that is generated shortly after the machine on which the paging file exists is started. The session key, which is used both for encryption and decryption of the paging file data, is stored in volatile memory, so that the key is not persisted across boots of the machine. Since the key is not persisted across boots, old paging file data that was stored prior to the most recent boot cannot be recovered in clear text, thereby protecting the data from observation.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.