Data Erasure Methods PDF Print E-mail

Enterprises have traditionally approached data erasure from a tactical, ad-hoc, or “point-solution” perspective. Unfortunately, the complex issues associated with data erasure require a more strategic approach that involves multiple decisions across several important areas to meet the needs of today’s enterprise business environment. Advantages and disadvantages that are associated with these issues include:-

1.    Physical Destruction

With physical destruction, hard drives and other storage media are destroyed to prevent access to data. This involves either shredding the drive into tiny pieces or drilling a series of holes into the hard drive platters. This approach doesn’t always destroy the data, but makes the drive inoperable, thereby preventing data recovery by ordinary means.


  • this approach is an effective way of preventing any subsequent data recovery if the procedure is carried out correctly. Large amounts of media can be destroyed at once, and different forms of media (such floppies, CDs, DVDs, or removable drives) can be destroyed simultaneously with the magnetic hard drives.


  • Physical destruction neglects to recover any residual value for the hard drive; so this approach is not viable with expensive, large-capacity drives that could be reused within the enterprise or sold the secondary market. Due the cost of the equipment required, destruction is typically outsourced, thereby increasing the possibility of exposure of confidential data. Physical destruction also poses an environmental risk due to the toxic debris created, possibly breaching EPA regulations.

Finally, if performed incorrectly, data can still be recovered from the remaining fragments of the storage media.

2.     Degaussing

Degaussing a hard drive uses strong electromagnetic fields, ideally destroying all the magnetically recorded data on the drive and renders the drive inoperable.


  • Degaussing in fast and capable of destroying all data on a hard drive or other magnetic media. The purchase of a degaussing machine is usually a one-time investment, which mitigates costs.


  • While degaussing ensures the destruction of older drive technologies, newer drives with thicker shielding require a stronger electromagnetic field to ensure complete erasure. Unfortunately, with variances in drives designs, there isn’t a uniform way to guarantee that degaussing will completely erase all of the data and protect the enterprise from a security breach.

Also, this option can be only used on magnetic media, which will not reliable destroy all the data if procedure are not carefully followed. Due to the nature of magnetic fields, care must be taken to the prevent nearby components and equipment from being damaged.

3.    Re-Formatting the Drive

Despite the growing awareness of the ineffectiveness of re-formatting as a data erasure method, many organizations still remain ignorant of its security risks.


  • There are no advantages to this method since the data is not completely erased.


  • All “Delete” and “Format” commands only change the drive’s File Allocation Table (FAT) and do not actually erase any data. Only the address tables pointing to the data files are erased. The data is still intact and can be easily recovered using software utilities, readily available on the internet.

Until the “deleted” data is completely overwritten with new data, it still exists and poses significant security risks for identity theft, litigation and lawsuits, and possible incarceration. As a result, this method of data destruction should be avoided.

4.    Software Overwrite Solutions

Software solutions that overwrite data on top of existing information employ a process of writing patterns of meaningless data into each of the drive sectors using a combination of 1’s and 0’s.


  • This option is the most effective and convenient way of permanently destroying data. Once the device has been erased, it can be reused or resold, preserving the functional and remarketing value of the asset. In some cases, the tool can also be deployed over a network to target specific computers or drives. It can also produce reports verifying proper completion and including a defect log that lists any bad sectors that could not be overwritten by the software. Reports satisfy compliance requirements and often include the drive serial number, extent of data erasure, name of the erasure procedure, the technician, and any errors that occurred during the erasure process.


  • Many organizations still rely on older standards and recommendations for three to seven overwrite passes, which combined with inadequate software tools, makes the process of wiping a standards PC drive take several hours. In addition, not every overwrite program offers complete security. For example, freeware overwriting tools available on the Internet are unable to access the entire hard disk which might include hidden/locked directories or remapped sectors of the drives. In the event of incomplete results, some data may remain intact, compromising security. Also these solutions cannot be used if the storage media is damaged or can’t be over-written.

5.    Dead Storage

Unable to make a decision from fear of a security breach or from simple lack of awareness of the alternatives, many companies simply store their hard drives and computers to ensure that data doesn’t fall into the wrong hands.

In fact, a large segment of enterprise organizations choose storage as their primary method of asset disposal. According to a survey of 320 IT professionals conducted by Gartner Research during a recent IT conference, storage was the third-most-common-method of dealing with obsolete PCs and servers of the companies that were surveyed, approximately one-quarter indicated that they store over 30 percent of their obsolete PCs and serves.


  • Stored equipment and hard drives can be re-purposed to other departments quickly and easily, which can reduce installation time and acquisition costs.


  • When computer equipment is stored, there is a tendency for employees to pilfer that equipment – particularly hard drives- thereby creating the very security risk that the storage was intended to avoid. Stored equipment can also yield a negative value due to the rapidly depreciating nature of technology equipment. this disadvantage grows as the cost of storage increases and the value of the equipment plummets. Further, if the application and system software is not de-installed upon asset transfer, the enterprise could be out of compliance with the terms of their software license.

A matrix of the advantages and disadvantages of data security measures is illustrated below in Figure 1.

Figure 1: A Data Security Measures Matrix


Do Nothing

Format Drive

Physical Destruction

Software Overwrite


Peace of mind






Reduced Risk






Auditable Compliance






Proven Solution


















Future Prof






Data Erasure Methods

In order to mitigate the risks of information fraud while ensuring compliance with the government regulations, privacy concerns, and intellectual-property rights issues, it is the responsibility of every company to design effective data leak preventions policies and data erasure procedures for IT assets destined for disposal or re-sale.

Here are seven important steps to formulating a corporate-wide data erasure policy:-

1. Determine the Most Feasible Solution

Each company’s data erasure policy should be based on several business factors such as the size of the organization, the frequency of data erasure and disposal, and specific industry requirements. For example, purchasing expensive data erasure equipment may not be financially feasible for a small business. On the other hand, storing thousands of outdated computers is never feasible for a large enterprise since it usually presents a security risk. To determine the most effective solution, businesses should assess their existing resources and add outside expertise where resources are lacking. Enterprise should also plan for future needs as organizational expansion and/or acquisition can alter requirements and deployment options.

2.    Calculate Costs and Formulate a Budget

Most enterprises have a budget for IT equipment and services, but few have one for data erasure and asset disposal. While there are several alternatives, each has risks which carry a cost. By deploying an effective data erasure strategy, an enterprise can often recoup the remaining value on equipment by reselling it within two to three years after acquisition. Typically IT assets are fully amortized in three years. The remaining remarketing value (RMV) is not related to amortizations schedule. However, somewhere after 3 to 5 years (servers and storage hold their value longer) the RMV will go to zero (but the disposal cost remains) and the asset becomes a liability.

3.    Assign Roles and Responsibilities

Where will the ultimate data erasure decision lie? Will it be with a “C-Level” business executive, an IT Director, or a Purchasing Manager? Data erasure is not a technical or operational issue; it is a risk and liability matter. As a result, the decision-maker should be the individual most impacted if something goes wrong, such as a corporate risk manager or security architect. In either case, data erasure is a process that requires an owner. Additional personnel matters include determining the number of people required for data erasure, where they will be located and what role Human Resources will play. Since personnel costs can be significant, staffing requirements should be considered equally with technical and procedural issues.

4.    Pick the Disposal Location

The facility where data erasure is performed can impact both the quality and security of the erasure process. For example, on-site data erasure provides the most secure option by ensuring that sensitive data doesn’t leave the enterprise. Using an off-site or third party facility to perform the data erasure adds steps to the process, which require verifiable facility security and documentation. Important questions to ask include:-

Does the location provide a Statement of Work (SOW) detailing the steps in their erasure procedures? Can they provide certificates for regulatory compliance reporting? Have they installed security cameras for surveillance in designated work areas? Do they use sealed and secure containers to prevent unauthorized access during shipping? One effective option is to use a combined approach where both on-site and off-site facilities are employed. For example, an enterprise could designate storage media with the most sensitive business data for internal erasure, while allocating media with less-sensitive information for off-site erasure and disposal.

5.    Choose a Qualified Service Provider

When considering the person or company responsible for data erasure, two factors to consider are control and cost. A policy that uses internal employees or brings outside service providers on site, provides the greatest control, but incurs higher costs. Shipping media to an off-site location affords a lower cost, but yields less control. Both options are viable, but risk versus cost considerations must be weighed.

6.    Plan Desktop/Data Center Device Management

Data Center equipment is deployed, run, and managed differently from desktop PCs and notebooks. As a result, the process of removing storage devices from equipment such as a network server or array to replace the storage media designated for erasure can impact essential business functions. Servers or storage arrays that are running mission critical applications can’t be easily powered-down or decommissioned without costly time-consuming procedures to bring them back online. The sheer volume of this task may make it more cost-effective to bring in qualified experts rather than risk disruption of crucial business functions that might be caused by inexperienced employees trying to perform the task. Before deciding, ask: Do internal employees have the skills and the time to properly perform the tasks given their existing priorities? Might it be more cost effective to pay outside experts if they can complete the process more quickly and with less or no down time? Will using outsiders yield more effective results or create additional, more costly problems?

7.    Research Regulatory and Reporting Requirements

Any public and private company in a regulated industry that handle sensitive information must understand the necessity of generating an audit trail and producing the reports required to comply with the federal and/or state regulations regarding asset disposal data erasure. Reports should include lists of the disposed or erased items, their serial numbers, how the data was erased or the asset was destroyed, and the disposal procedure(s). The advantage of enterprise-grade software overwriting solutions is that they can generate these reports and help protect enterprises from compliance litigation.

Considerations When Determining an Enterprise-Class, Data Erasure Strategy

There are several components that comprise an effective enterprise-class data erasure strategy. Some of the critical questions to ask and essential criteria to consider when developing data leak prevention and asset disposal policies include:-

  • Regulations

What specific industry regulations or legislation (e.g. GLB, PCI, HIPPA, and FACTA) is our organization subject to and what are their requirements for data and IT asset disposal?

  • Internal Policies

Do we have written policies that reflect these requirements? Is our organization able to effectively enforce those policies?

  • Audit-Related Factors

Are any of our existing policies and practices auditable?

Many corporate IT departments use simple overwriting functions available in many disk utilities. However, these tools may have significant drawbacks which could compromise an organization’s security. Highly effective enterprise-grade overwriting software must have the following functions and capabilities in order to ensure the integrity of the data sanitization process:-

1.    Security & Performance:-


A compatibility with, or capability to run independent of, the OS loaded on the drive.


The capability to run independent of the type of hard drive being sanitized (e.g., Advance Technology Attachment (ATA)/Integrated Drive Electronics (IDE) or Small Computer System Interface (S CSI) type hard drives).


A capability to overwrite the entire hard disk drive independent of any Basic Input/Output System (BIOS) or firmware capacity limitation that the system may have.


A capability to detect, report and overwrite locked and hidden sectors such as HPA, DCO, remapped sectors as well as wiping hot spare hard drives in RAID configurations.

2.    Reporting & Auditability:-

  • Certification
  • A capability to provide the user with erasure certificate/report indicating that the overwriting procedure was completed properly.
    • Hardware Configuration
    • A capability to identify and report vital HW configuration information with computer serial numbers and asset tags.
    • License Harvesting
    • A capability to identify and report e.g., main SW serial keys for license harvesting.
  • Digital Signatures

  • A capability to ensure report’s integrity with digital signatures.

  • Integration of Data

  • A capability to provide means for easy report integration e.g. to asset management systems.

Finally, a qualified service provider should have the following attributes:-

  • They must be insured (a minimum of USD 1 million).

  • They must be reputable and use proven software and operational techniques.

  • They must have certified engineers for onsite and support.

  • They must be able to provide certificates that include serial numbers.

  • They must be able to provide erasure reports to verify each disk that has been erased.

  • They must provide alternatives for both software based erasure and data destruction with an ability to combine solutions to keep operating costs low.

  • They must be able to provide references.


The rapid rise in corporate information theft and fraud has made the issues of data erasure and IT asset disposal as important to an enterprise as the integrity of their corporate networks. An organization that fails to properly secure its business information when assets leave the premises risks severe penalties on a variety of legal, financial, and marketing-related fronts.

A sound and well planned end-of-life IT asset and data policy should be an essential component of every organization’s corporate information strategy. Disposal and erasure methods should not be chosen on price alone. There are advantages and disadvantages to different disposal alternatives which should be carefully evaluated in light of each organization’s unique requirements.

The three most important business advantages of a well structured data erasure and asset disposal policy are:-

1.    To Reduce Business Risks

A well-planned data erasure policy reduces the potential for costly risks, liabilities, regulatory requirements and public embarrassments that can occur when business data falls into wrong hands.

2.    To Ensure Data Security

A well-orchestrated data and asset disposal policy ensures the security of business information, thereby protecting existing relationships with customers, employees, and business partners.

3. To Achieve Greater ROI

A thorough and regular data ensure policy enables an organization to safely remarket their aging IT equipment, thereby reducing the costs associated with implementing data leak prevention and asset disposal policies.

In order to protect themselves from the risks and liabilities of proprietary data getting into the wrong hands, business should create and implement a formal data erasure policy and should align themselves with qualified and experienced data erasure and asset disposal resources who can provide the most cost-effective, secure, and best protection options.


Did You Know

arrow Identity theft is the top consumer complaint in the USA according to the Federal Trade Commission.

arrow US consumers reported fraud loss totalling more than $1.1 billion in 2006.

arrow Credit card fraud (25%) was the most common form of reported identity theft in the US in 2006.

arrow More than 100 000 people are affected by identity theft each year in the UK

arrow According to Privacy Rights Clearinghouse, more than 350 data loss incidents involving more than 140 million records have occurred since February 2005

arrow Organisations are obliged by law to take take adequate steps to ensure the proper disposal of data



Now: 2018-11-14 06:11

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