Cryptographically protected paging subsystem

摘要

A method and system for maintaining integrity and confidentiality of pages paged to an external storage unit from a physically secure environment. An outgoing page is selected to be exported from a physically secure environment to an insecure environment. An integrity check value is generated and stored for the outgoing page. In one embodiment, this takes the form of taking a one-way hash of the page using a well-known one-way hash function. The outgoing page is then encrypted using a cryptographically strong encryption algorithm. Among the algorithms that might be used in one embodiment of the invention are IDEA and DES. The encrypted outgoing page is then exported to the external storage. By virtue of the encryption and integrity check, the security of the data on the outgoing page is maintained in the insecure environment.