Data Sanitization : What and how
What is Data Sanitization.
Data sanitization is the act of intentionally destroying the data stored on a storage device, permanently and irrevocably , beyond recovery.
Lets take an example
If a bank is discarding the old computer systems , they must ensure that all the hard drives have been sanitized - all the data has been removed permanently. They must further ensure that it is beyond recovery so that nobody will be able to recover any data using data recovery tools.
Deleting the files, or formatting the storage media will not result in a permanent, irreversible data removal. They have to use a data sanitizing device ( a Degausser or a hard drive shredder) to ensure the data security. If they have further compliance, they many need an audit log of all the media that's been sanitized.
Its not hard to see why you must sanitize your storage media . Any unsanitized device leaving an organizations premises can be exploited and used to gain access to any critical information which might be residing on the data storage media like SSD, HDD or tapes. Extent of the damage will depend on how much information was stored on the media - if its medical history or financial information of the clients, it would be a huge disaster for the organization and their clients . Reputation of the corporation may be tarnished, and there may be financial impacts by the regulatory bodies.
In Recent years, sanitization has become even more crucial because
- More IT devices are being discarded as the device lifespan is becoming shorter
- More and More Customer Sensitive Data is being stored to enhance customer experience.
- Data Thefts are increasing. Many Data Thieves have realized that the easiest way to get their hands on data is to skim through old hard drives.
Methods of Sanitization
There are 3 major ways to Sanitize the media.
Degaussing is the process of subjecting the magnetic media to a very strong magnetic field. This is done using specific devices called Degaussers which are capable of producing very high magnetic field. Media is placed in a chamber, and at the press of a button the magnetic field is applied. The whole Degausser itself is shieled so that no magnetic flux is escaped.
Advantage of Degaussing is
- Its extremely Fast : Takes a few seconds per media, irrespective of the size.
- There is no noise, no debris, nothing to discard.
- There is no maintenance required .
- Degaussers are small in size. The smallest one we sell is the size of a microwave oven.
A Degausser only works on magnetic media like hard drives and magnetic tapes . Degaussers don't work on SSDs because SSDs don't use magnetic platters to save information. Further the degaussed media can not be reused.
Destruction ( Hard drive Shredding)
Physical Destruction is the process of physically damaging the hard drive, which may include breaking the drive, shredding the drive , or puncturing holes in the drives. Tapes are shredded with tape shredders. Biggest Advantage of Destruction is that its physically verifiable. You can physically see the media being destroyed. In contrast a degaussed media is visually exactly same as the undegaussed media.
Destruction however is noisy, involves large devices which need maintenance since there are physically moving parts and the end result is always debris that more difficult to discard compared to a wholesome media.
Data Wiping through Rewrite
Rewriting the media several times with a random pattern results in a irreversible removal of data .Many algorithms exist with the most fail proof called a 7 pass method in which Random data is written and erased 7 times on the media.
You don't need any specific device to do this. You can do it through software if you can mount the media and you have the time to write on it 7 times full capacity ( or full length of tape). This is a time consuming process and depends on the capacity of the media you are sanitizing and the data transfer rate between the host and the media.
Hard drive copiers also double up as Data wipers. They have multiple ports, so you can sanitize many hard drives at the same time.
Biggest advantage of Data Wipe through rewriting is that you can reuse the media.
Weather you do DoD rewrite, degauss or destroy your media ; all these methods are equally good and effective, as long as they are executed.