Secure Erasure of Digital Files
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorAvelino Andretti Benavides
Life of this patent
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Abstract
One or more target files are securely erased from a host storage medium such as a disk by overwriting the target files not just with “O's,” “1's” and/or random data, but also (or instead) by overwriting them with portions of other, selected, innocuous files found on the same medium. By booting the host using a secondary, preferably external mechanism, before the host operating system is allowed to load, logging of file accesses and process execution by the host OS is circumvented. Post-replacement fragmentation and defragmentation may also be used to further reduce the detectability of the erasure, and the success of the process may be evaluated using statistical analysis.
Claims17
A method for securely erasing data from a computer-readable host storage medium in a host computer system which has a host operating system, and in which the host storage medium stores separately read/writable files in at least one used space comprising:
- selecting at least one of the files as a target file for secure erasure;
- selecting a set of replacement data from the used space of the host storage medium that is representative of at least one source file in the used space;
- and
- replacing the target file on the host storage medium with the replacement data.
A computer-operated mechanism for securely erasing data from a computer-readable host storage medium in a host computer system, which has a host operating system, and in which the host storage medium stores separately read/writable files in at least one used space
- the computer-operated mechanism comprising:
- a secondary computer-readable storage medium storing instructions executable by the host computer system, including:
- a file selection module that selects at least one of the files as a target file for secure erasure;
- and
- a homogenization module that selects a set of replacement data from the used space of the host storage medium that is representative of at least one source file in the used space, and that replaces the target file on the host storage medium with the replacement data.
Dependencies are inferred from the claim text.