Data Disposal

With the vast amount of data being collected every day, data governance and security is becoming increasingly important. While many people acknowledge the significance of proper data collection and usage, their efforts fall short when the data is no longer needed. A key part of any data security plan is data disposal. Failure to dispose of data safely can lead to serious breaches of data-protection and privacy policies, compliance problems, and added costs.

What is Data Disposal?

Data disposal, also called data destruction, is the process of eliminating data stored on any form of electronic media so that it is completely unreadable and can’t be accessed or used for unauthorized purposes. When data is completely deleted, it’s no longer readily accessible by the operating system or application that created it. Disposing of data is necessary when there’s an upgrade, replacement, or change in ownership of hardware, and for certain situations in the cloud. If data isn’t disposed of properly, important, and possibly confidential, information can get into the wrong hands and bear serious consequences. Let’s take a look at the specifics of data disposal.

Data Disposal Methods

Three data disposal methods.There are a few options for in-house data disposal (we’ll talk about data in the cloud a little later) and before choosing one, it’s important to consider three main factors: Time, cost, and validation.

  • Time – when thinking about time, it’s important to be logical according to your storage capacity. Is disposal something that’s required often? Does your business have a lot of data to go through? Some methods are more suitable than others for getting rid of data very frequently.
  • Cost – when thinking about cost, it’s important to keep your business’s budget in mind. Can you afford to completely destroy data storage hardware or does it need to be reused? Can you afford to buy specialized destruction hardware or should you pay someone else to do it? Some methods will be more cost effective than others depending on your needs.
  • Validation – when thinking about validation, it’s important to know what’s required of your business in terms of security. Is data disposal a regulatory compliance requirement? How will you prove to auditors that you’ve met the requirements? Some methods will work better than others, especially when disposing of data strictly for security reasons.

Once you’ve put thought into what qualities your business has in relation to data disposal, it’s time to take a look at the actual means of destruction. There are three main ways of handling in-house data disposal: Overwriting, degaussing, and physical destruction. We’ll discuss the details of each method as well as some advantages and disadvantages.

Overwriting

Overwriting is simply covering up old data with new information. By recording over old information, you destroy it in the process, rendering anything left completely unreadable. This technique is also called data wiping. While you may think deleting a file and creating a new one in its place counts as overwriting, reality is it doesn’t. Data destruction software must be used to overwrite the available space with random data until it is considered irretrievable. The software can be used on selected data or on an entire medium, as long as all necessary storage regions are addressed.

  • Advantages:
    • Overwriting once is usually enough for most data removal situations; high security applications may take multiple overwrites, however.
    • Able to pick and choose what gets overwritten
    • Easily executed
    • Low cost option for some businesses
    • Environmentally friendly
  • Disadvantages:
    • Can be time consuming depending on the storage capacity
    • Some data may be unable to get overwritten due to extra protections (inaccessible regions, host-protected regions)
    • Limited to nonexistent protection during the actual overwriting process, causing drives to be subject to intentional or accidental parameter changes.
    • Multiple software licenses may be needed for separate storage drives
    • Process is ineffective without measures to check for quality assurance
    • Only works when the storage drive isn’t damaged and is still writable

Degaussing

Degaussing is the process of erasing the magnetic field of the storage media. A degaussing device is used to destroy data on magnetic storage tapes and disk drives by changing the magnetic field. When the degausser is applied to the magnetic fields the information is scrambled into random patterns, making the data stored in the magnetic field unreadable. When applied to magnetic storage media, degaussing purges the entire storage medium.

  • Advantages:
    • Makes data completely unrecoverable, so it works well for highly sensitive data
    • Quickly disposes of data
    • Effectively removes all data from a drive
    • Can use a degausser on already damaged hard drives
  • Disadvantages:
    • Strong degaussers can be expensive and heavy
    • Electromagnetic fields on degaussers can be strong enough to damage other nearby equipment
    • Need to know the exact strength of degaussing needed for each storage medium
    • Storage drive becomes permanently damaged and can’t be reused
    • No way to ensure all data is destroyed because the drive becomes inoperable

Physical Destruction

Physical destruction disposes of data by using a variety of techniques and machines to physically damage the storage medium beyond use and repair. Means such as heat, magnetic fields, shredding, or pulverizing are used to physically destroy data on different types of storage solutions. No matter the means of destruction, it’s crucial that in the end, every piece of data becomes irretrievable. While physical destruction may seem easy enough to do on your own, it’s recommended that a professional with heavy duty equipment take care of this method of data disposal. This is because computer experts have come a long way in data retrieval, so it’s crucial that all data becomes inaccessible.

  • Advantages:
    • Highest assurance of absolute destruction of data
    • Large amounts of devices can be destroyed at once
    • Different types of media can be destroyed at once
  • Disadvantages:
    • Can be difficult to reliably audit a physical destruction process
    • Most physical destruction methods leave large parts of the storage medium intact, even if the drive is inoperable; data could be recovered using special methods.
    • Expensive due to heavy duty mechanisms needed for destruction
    • Not environmentally friendly

Disposal in The Cloud

Data disposal in the cloud.

Cloud computing creates new challenges for data destruction. The problem is simple — in the public cloud, vendors own and operate the hardware they use, so clients can’t necessarily be assured that their data, residing in the cloud’s hardware, is ever completely destroyed. Most of the time, cloud vendors want to reuse hardware for multiple clients over time and only truly sanitize storage medium once they are decommissioned forever. This is an issue for many businesses because they need to be sure their data is properly disposed of after they’re no longer using the cloud vendor. In the private cloud, businesses have access to the infrastructure and more control over how they dispose of data.

Cloud vendors that want to get ahead of competitors should seriously take into consideration data disposal procedures. Investing in the right solutions can help erase client data in an efficient, cost-effective way. As a client, here are three things to watch out for when considering data disposal in a cloud service model:

  1. Have an established process in service agreement: A service level agreement between a cloud vendor and client should explicitly state all terms and expectations of the partnership, including plans for data disposal. Clients should be able to answer the following questions: How is my data disposed? When does disposal occur? How and when will I be notified of data disposal? The answers to these questions should guide the process of data disposal for the cloud vendor.
  2. Have a standardized data disposal procedure: Due to the importance of proper data disposal, it’s incredibly important to have a standardized procedure. That way, vendors can be confident in properly replicating best practices at all times. The procedure can consist of any method or combination of methods desired, just make sure there’s a concrete plan that is followed for every situation.
  3. Have a documentation process: Keeping track of who has handled data, even during the disposal process, is very important. It should be easy to prove that only authorized users had access to storage devices, and that other people were never able to tamper with any data. Vendors should establish a process to fully track and document data disposal so they can create an audit report to verify with clients after completing destruction. Clients can also take this measure into their own hands by requesting that their cloud vendor ship decommissioned drives to them for out-of-cloud disposal.

Conclusion

An effective data disposal strategy is the first line of defense against identity theft, breach of confidentiality agreements, and stolen information. Each in-house data disposal method has its advantages and disadvantages, and a decision should be made based on important factors like time, cost, and validation. Disposal in the cloud can be hard to control, but there are factors to keep in mind that can guide the process. Human error poses a huge issue with any data disposal method, so maximum precaution should be taken to prevent mistakes. Some businesses make their data disposal processes very thorough by using multiple methods of destruction. This ensures complete disposal of data, even when human error occurs. The bottom line is that data must be completely destroyed or erased in order to protect those who have a stake in your business.

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About Bryn Burns

Hi! I'm Bryn Burns. I am a current senior at Virginia Tech pursuing degrees in Statistics and Mathematics. Data science and visualization are two things I'm very passionate about, as well as working with numbers and helping people learn. I'm thrilled to share my knowledge here at The Data School!