Secure file erasure
US5265159A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 23, 1992 |
| Grant date | Nov 23, 1993 |
| Priority date | — |
| Expiry date | Jun 23, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2221/2143
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method of securely deleting a file on a storage medium of a computer system so that it is not readable, wherein an encryption algorithm is used to encrypt the data in the stored file prior to a conventional deletion process. The present invention permits a user to erase files from a permanent storage space and in a manner that makes the file totally unreadable by others. When a user requests deletion of a stored file, the file is encrypted so that it is not readable. The user has an option to undelete the file by decrypting the file as long as this operation is done before the storage space is used by another program. When the secure deletion method is used, no utility program can recover any information from the deleted file. To an intruder, the storage space is encrypted to look like random bits. Therefore, no information can be retrieved nor derived from the encrypted, deleted file. If the user does not expect to undelete the information, a one-way encryption algorithm is used to increase the speed of secure deletion of the file. If the user does not destroy the key, he or she may recover the file. This method restores the file directory pointer to the file, and decrypts the e…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.