Each application we use creates its own history data, access logs, temporary data files complete with the time and date of its activity. In order to ensure absolute corporate and personal security, all this information, along with all recycle bin activity should be securely deleted.
What should one do to ensure that all the data on your hard drive or any other optical or magnetic media is safely erased when you discard or resell your computer or hard drive? Can a simple deletion of files and emptying the recycle bin do the trick or is reformatting the hard drive safer?
For this, one needs to know how data is stored on a hard drive and what happens when we delete a file or erase any information. When any information is written on a drive, the location of that information is stored in a file that resembles a table of contents in a book. When a file is deleted, this table of contents is updated to inform the computer that the space on which the deleted information was placed is now available for any new data to be stored. The actual data is not deleted until it is overwritten by any new data. This fact is responsible for facilitating simpler undelete tools or other more advanced data recovery techniques to recover data that has been physically or electronically destroyed.
Does this mean that data once stored on a computer is always at the risk of being viewed by someone else? This is not the case though. There are ways through which one can securely remove data from hard drives and other media in a manner that cannot be undone. One can securely delete files, folders, evidence of internet activity and other sensitive data. Before knowing about various techniques available to ensure permanent data destruction, you need to decide whether you want to delete the data only or you want to destroy the hard drive on which the data is residing.
If you want to erase the data, only then should you remember what will not work: deleting the data and emptying the recycle bin, reformatting the hard drive, reformatting and reinstalling another operating system. The procedures you can use which will destroy or erase your data so that the average individual will not be able to recover anything from your hard drive are:
1. Use Wipe Facilities: There are various standardised data wiping software available that will completely sanitize or wipe information off the hard disk. Some of the good ones available include Darik’s boot and nuke, Active @ Kill Disk and so on. Use these wiping utilities to destroy any data on the hard drive before giving, selling or disposing off your computer.
2. Data Shredding Programmes: While giving away your computer you do not need to eliminate all the valuable software along with your personal data. To completely destroy any files while saving the software, you can use a data shredding program such as a digital file shredder from Stomp Soft. The principle on which it works is that it actually overwrites the files.
3. Degaussing a Hard Drive: One step further is to degauss the hard drive. Degaussing is a process in which the magnetic media is erased using a reverse magnetic field to scramble the electronic data, thus making it unreadable. Unfortunately degaussing machines are expensive and not worthy purchases for the average consumer. However, you can send your hard drive to a degaussing company and for a little amount you can have your hard drive completely degaussed and/or destroyed.
4. Physically Destroying Hard Drive: Physically destroying a hard drive is by far the most effective method for the average person to ensure the safety of their data. There is no better way to completely destroy your data than to render the device that stores it unusable. If your personal data security justifies the extra effort, put on protective eyewear and gloves, then break the storage media. It could be smashing the hard drive with a sledgehammer, drilling holes into the drive, tearing the drive apart and destroying the platters, shredding the drive and so on.
Another sure shot way to thwart data recovery is to melt down all the aluminum contained in the platters. Slagging of the drive would distort the shape of a readable disk and would nullify the magnetic properties of the coated aluminum.
For optimum security, perform as many of the above procedures (wiping the drive, degaussing it, and destroying it) as you can. If a drive is wiped, degaussed and destroyed the chances of recovering the data are negligible.
