The Most Effective Data Erasure Strategies for Different Devices

Written By Girish Gola
Approved By Vishal Sharma
Updated On Feb 28, 2023
Min Reading 6 Min

Whacking your device with a hammer surely is an effective way to destroy data. But you wouldn’t want to resort to that for an expensive laptop, would you?

Various devices store data in different ways. So some methods work well with one device that wouldn’t change a thing for another device.

In this guide, we discuss the most effective data destruction strategy according to device types. Read to learn about:

The factors that influence the destruction method
How to make your decision
Data erasure methods according to device types
The NIST 800-88 standard
How to apply the standard to 5 common device types

Factors That Influence The Choice of Destruction Method

The ultimate purpose of a data erasure strategy is to ensure the complete removal of data such that it’s not recoverable. There are several data erasure methods. Each adheres to a certain standard and is more suitable for specific devices.

Here are the factors to consider when choosing a data destruction strategy:

Privacy concerns and risk tolerance

Data erasure methods like disk formatting and deleting can help you save money. But they are fairly easy to override and recover data. So you would select these methods for less sensitive data.

Type of storage device

Degaussing doesn’t work on SSDs but is effective for hard drives. Similarly, some erasure methods are effective for some devices.

Environmental concerns

Physical destruction renders the device unusable making it another addition to landfills.

According to a report by the Central Pollution Control Board, India generated 1,014,961 tonnes of e-waste between 2019-2020. E-waste can leak toxic matter into the ground and water sources. The most dangerous effects of this is kidney and neurological disorders.

Proper management of e-waste is crucial if we’re to reduce our impact on the Earth. That’s why organisations have sustainability policies in place. And if they do, software-based erasure methods work the best.

How to Choose the Data Erasure Strategy?

Choosing the best data destruction strategy is up to you and your company’s policies. The best practice when picking a data erasure strategy is to have a standard list of questions. The answers to these questions should reveal the data destruction strategy you should pick.

Here is a decision flowchart that will make the task easier for you:

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Overview of Media Types and The Ideal Data Erasure Strategy

As mentioned previously, the data erasure strategy depends on the storage device. The following table relates the data erasure strategy to the device types.

Device Type	Storage Mechanism	Best Data Removal Method
HDD	Non-volatile magnetic	Physical and digital: Multi-pass pattern wiping, disintegration, incineration
SSD	Non-volatile solid-state memory	Physical and digital: Multi-pass pattern wiping, disintegration
Flash Drives and USB	Non-volatile solid-state memory	Physical and digital: Multi-pass pattern wiping, disintegration, degaussing
Magnetic Tape	Non-volatile magnetic	Physical methods: degaussing, incineration, disintegration
CD-RW/DVD-RW	Write many digital optical disk	Physical methods: abrasion, incineration, disintegration

NIST SP 800-88 Standard of Data Eraure Strategy for Storage Device

The NIST SP 800-88 is a guideline that outlines how to safely erase data. Three data erasure methods are used to sanitise media under NIST 800-88. These methods are device and data-specific.

These are the sanitization techniques defined by the guideline:

Clear

Logical techniques to sanitise data are applied through standard Read-and-Write commands such as rewriting. Block erase, and cryptographic erase are some other data erasure methods used under the Clear technique.

Effective for: ATA Hard Drive, SSDs

Purge

This is typically used for confidential data as it makes data recovery impossible. Degaussing and cryptographic erasure are two of the data erasure strategies used.

Effective for: HDDs and SSDs

Destroy

Destroying is a purely physical data destruction strategy. You can use techniques like incineration and shredding to sanitise data.

Effective for: Almost all types of devices

The NIST 800-88 Standard for Data Destruction: 5 Most Common Device Types

Here are the recommended methods to sanitise 5 different devices using the NIST 800-88 standard.

HDDs

Hard disk drives are non-volatile storage devices that maintain data even when turned off. HDDs are installed in laptops, CPUs, and servers, among many others.

Here’s how to apply the NIST 800-88 standard to HDDs.

Clear	For HDDs, the clear overwriting pattern should consist of at least one pass. It should have a fixed data set (like all zeros). You may also use multi-pass overwriting methods, but only in specific circumstances.
Purge	You may degauss the HDD with an approved automated degausser. ATA Hard Disks have a security feature called the “Secure Erase Unit” command. This command may be used to purge the device. Use ATA’s sanitise device commands if supported by the device.
Destroy	Physical methods like shredding, incinerating, or pulverising may be used.

If you’re using the clear or purge data erasure strategy, you should verify the destruction, unless you’re unable to do so.

External HDDs

Internal and external don’t have many differences in the way they store data. Their location is the biggest difference. And it is something that makes external HDDs more vulnerable to outside threats like theft.

Clear	You can do a one-pass or multiple-pass overwrite to clear your device. The data values should be fixed, ie.) all zeros or ones. It cannot be pseudorandom. The success rate of a data erasure strategy on External HDDs depends on the brand and model.
Purge	If the device is ATA or SCSI and can have sanitization commands delivered natively to them, then sanitise with that. The device’s instruction manual will tell you if you can perform purge techniques.
Destroy	You can shred, pulverise, or incinerate the device in a licensed incinerator.

If you’re using Clear or Purge methods, you must verify that the data erasure strategy was successful.

Some external HDDs can have encryption features that have hidden storage areas. So always check with the manufacturer whether your device has such an area and how to erase files from that location.

SSDs

Solid-state drives use integrated circuit assemblies to store data. SSDs are typically harder to sanitise than HDDs.

Here are some ways to sanitise SSDs following the NIST 800-88 standard:

Clear	If it is supported, you can use the SECURITY ERASE UNIT command. You can also overwrite the device with fixed data values using at least one pass.
Purge	You can use the block erase command on the device. After that, you can write binary 1s across the user addressable areas and perform another block erase. You can use the Cryptographic Erase technique with the Enterprise SSC or TCG Opal SSC. You can issue commands to change all of the media encryption keys.
Destroy	You can shred, disintegrate, incinerate or pulverise the device. All of this will make the data non-recoverable.

Mobile phones

This is probably the most commonly used storage device across the world. It is also the most discarded. So you will need a very secure method to sanitise the data if you’re going to throw away old phones.

Here are some ways to do that for iOS devices:

Clear	You can use the full sanitise option on the phone. It will be under the general settings. This method uses the Cryptographic Erase technique. You cannot verify the sanitization results when you perform a remote wipe.
Purge	You should perform the same steps as in the Clear method for the Purge method as well.
Destroy	Physically destroy the device using methods like incineration or shredding.

USB Removable Media

Pen Drives, Thumb Drives, Memory Sticks, and Flash Memory Drives are all examples of USB removable media.

Clear	You can use tested overwriting tools to sanitise the media. You must use at least two overwriting passes to efficiently sanitise the data. The second pass should complement the first one.
Purge	Most USB Removable Media don’t support Purge commands.
Destroy	Most USB Removable Media don’t support Purge commands.

USB devices are comparatively inexpensive. So destroying it would be the most effective way to sanitise the media.

Data Destruction Strategy Decisions

NIST 800-88 is the golden standard to abide by when sanitising your devices. If you need the device intact, then using NIST-certified software is a safe bet to sanitise your device. You can use BitRaser, a data eraser software that follows the golden standard.

If the device is disposable, then you can use physical destruction techniques. That will leave absolutely no trace of your data.

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The Most Effective Data Destruction Strategies for Different Devices