Methods of sanitizing a flash-based data storage device

Abstract

A data storage device includes one or more non-volatile, blockwise erasable data storage media and a mechanism for sanitizing the media in response to a single external stimulus or in response to a predetermined physical or logical condition. Optionally, only part of the media is sanitized, at a granularity finer than the blocks of the medium. Setting a flag in an auxiliary nonvolatile memory enables an interrupted sanitize to be detected and restarted. Optionally, a “death certificate” verifying the sanitizing is issued. Preferably, the media are configured in a manner that allows atomic operations of the sanitizing to be effected in parallel.

Description

[0001] This is a Divisional of U.S. patent application Ser. No. 10 / 449,066 filed Jun. 2, 2003, which is a Continuation-in-part of U.S. Provisional Patent Application No. 60 / 457,021 filed Mar. 25, 2003.FIELD AND BACKGROUND OF THE INVENTION [0002] The present invention relates to nonvolatile storage devices and, more particularly, to methods for sanitizing a flash-based data storage device and to a flash-based data storage device particularly adapted to the implementation of these methods. [0003] For as long as data has been stored digitally, there has been a need to erase classified data, from the medium in which they are stored, in a manner that renders the data unrecoverable. Such an erasure is called “sanitizing” the medium. [0004] The most common nonvolatile data storage devices use magnetic data storage media, in which data bits are stored as magnetized regions of a thin ferromagnetic layer. It is difficult to sanitize such a medium. The usual method of sanitizing such a medium ...

AI Technical Summary

Benefits of technology

"The present invention provides several improvements to the methods and devices for sanitizing flash media and other non-volatile data storage media. These improvements include selectively sanitizing only a portion of the medium, applying sanitizing procedures to data stored in units smaller than the blocks, and sanitizing the medium using a single external stimulus. The invention also includes a data storage device with a mechanism for sanitizing the medium in response to a single external stimulus. These improvements make it easier to effectively sanitize flash media and other data storage media, ensuring their cleanliness and reliability."

Problems solved by technology

For as long as data has been stored digitally, there has been a need to erase classified data, from the medium in which they are stored, in a manner that renders the data unrecoverable.

It is difficult to sanitize such a medium.

This method requires a long time (minutes to hours) to perform, and cannot be guaranteed to render the old data unrecoverable.

Degaussing devices are cumbersome, power-hungry devices that are external to the system whose data storage medium is to be sanitized.

The only foolproof way to sanitize a magnetic storage medium is to destroy it physically, which obviously renders the medium no longer useable to store new data.

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