SDelete

SDelete

 







One feature of Windows NT/2000's (Win2K) C2-compliance is that it
implements object reuse protection. This means that when an application
allocates file space or virtual memory it is unable to view data that
was previously stored in the resources Windows NT/2K allocates for it.
Windows NT zero-fills memory and zeroes the sectors on disk where a file
is placed before it presents either type of resource to an application.
However, object reuse does not dictate that the space that a file
occupies before it is deleted be zeroed. This is because Windows NT/2K
is designed with the assumption that the operating system controls
access to system resources. However, when the operating system is not
active it is possible to use raw disk editors and recovery tools to view
and recover data that the operating system has deallocated. Even when
you encrypt files with Win2K's Encrypting File System (EFS), a file's
original unencrypted file data is left on the disk after a new encrypted
version of the file is created.

The only way to ensure that
deleted files, as well as files that you encrypt with EFS, are safe from
recovery is to use a secure delete application. Secure delete
applications overwrite a deleted file's on-disk data using techiques
that are shown to make disk data unrecoverable, even using recovery
technology that can read patterns in magnetic media that reveal weakly
deleted files. SDelete (Secure Delete) is such an application. You can use SDelete
both to securely delete existing files, as well as to securely erase
any file data that exists in the unallocated portions of a disk
(including files that you have already deleted or encrypted). SDelete
implements the Department of Defense clearing and sanitizing standard
DOD 5220.22-M, to give you confidence that once deleted with SDelete, your file data is gone forever. Note that SDelete securely deletes file data, but not file names located in free disk space.

Using SDelete

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