Last update: October 28, 2008
Why it is insufficient to simply delete data and what wiping algorithms Acronis Drive Cleanser 6.0 uses
Introduction
Any file system registers a file by its name in the File Allocation Table (FAT) of a partition, while file data proper is stored in the sectors of a partition (hard disk) forming a chain. Deletion of files by means of an operating system only deletes a filename from the FAT, while sectors containing the file proper are considered empty. Data may be written to the sectors after deleting the file name from the FAT, but file data remains intact unless randomly overwritten. Deleting a file name in the FAT does not assure that data will ever be written over that files data sectors on the hard drive.
The Windows operating system, for example, allows users to easily recover a deleted file. There are many popular utilities that also serve this purpose.
It is more difficult to recover a deleted file in the Linux operating system. Files and data are bound up with greater complexity in Linux file systems such as Ext2, Ext3, and ReiserFS. But even under Linux, file data is still stored in disk sectors even after deletion.
Both off-the-shelf and rather inexpensive software, and a simple hardware device may be used to recover files, data, hard disk controller capabilities and even magnetic microscopy.
Formatting of a hard disk partition does not affect data written on the sectors of a hard disk in any way. Formatting just creates the data storage structure on a disk, this is known as a file system. If you just format a hard disk drive partition, only the names of files registered in the File Allocation Table will be destroyed - your confidential data will remain in the sectors of the hard disk.
Partitions existing on a disk are described in the Partition Table of the hard disk. Simple deleting a partition only makes the sectors of that partition considered unallocated. Files and data structures of the deleted partition remain intact. It is even easier to recover a deleted partition and all the files on it in this case than after formatting.
Solution
Acronis Drive Cleanser 6.0 uses trustworthy algorithms for secure data destruction.
All algorithms for destruction of data are based on multiple overwrites of data on the hard disk drive sectors, or if from a physical stand point - on multiple switching of recording material over the disk surface.
Algorithms used in national governmental standards provide for filling each byte of each hard disk sector with ones, random values, or complimentary values to those written during the previous pass. Wiping implies that there are multiple passes performed on the hard disk.
For example, the U.S. national standard offers writing of the following:
More information
Adoption of new or updated government standards for wiping data takes much more time than development of both software and hardware data recovery tools.
Modern computer hardware and electronics are inexpensive, do not require well-qualified personnel, and allow users to recover hard disk data from barely perceptible traces or repeatedly deleted records. While bureaucrats debate new technologies and algorithms for data security, individuals and groups will continue to develop new ways to erroneously recover sensitive data.
Therefore the most powerful algorithms of data destruction in Acronis Drive Cleanser 6.0 offer up to 99 customized passes on a hard disk.
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