Getting rid of your computer? Laptops, mobile phones and other devices may contain personal information that you wouldn’t want others to see, such as passwords and credit card information. Show
It’s important to properly delete any personal information before you sell or dispose of your hardware, so that it cannot be accessed by anybody else either by mistake or for malicious purposes. Also, if you have a device that is faulty think about what personal data is stored on it before you dispose it. Remember that just because a device will not turn on does not necessarily mean that the data is not accessible by someone. Personal data can be stored on any device with a permanent memory, including desktop and laptop computers, external hard drives, games consoles, mobile phones, tablets, faxes, printers, and removable memory such as that found in digital cameras. When deciding what to do, consider the type of media the data is stored on and whether or not this is easily accessible.
Where will I find my data?Desktop and laptop computers will have a hard drive inside where your data is stored. Above you'll see some common types of hard drives found in PCs and laptops. Don’t forget that you may have personal data stored on other memory types such as USB drives, CDs and DVDs and SD cards (eg in a camera or mobile phone). My data is in the cloud. How do I delete this securely?Securely deleting data from the cloud or other remote storage service cannot be achieved by you running overwriting software. You should contact your cloud provider to see what service they offer to securely delete the data. Where do I get overwriting software from?Software products which can perform the secure deletion of data are available from IT security firms. There are also other software products (often free) which you can download and use. However, when obtaining software from the internet you should make sure this comes from a reputable source and that you review evidence that the software has been tested against the claims that it makes. I cannot decide between physical destruction and overwriting.In choosing between physical destruction and overwriting, the main point to consider will be whether or not you want to use the media again. Physical destruction will completely destroy the media so it is only appropriate if you are sure that you do not want to use it again. What is the difference between data deletion and data destruction?Data deletion is when data is removed and is no longer available in plain sight or can easily be recovered. If you delete an item to your recycle bin, perform ‘quick format’ of your a hard drive or perform a factory reset of your device, you will be typically deleting data. However, data recovery experts can restore this data. Even with that said, data deletion is generally an adequate method of removing personal data from a device in most situations. In contrast, data destruction is when data is removed from your device and can never be restored, even be professional data recovery experts. Examples of data destruction are physical destruction of the data storage, secure data removal software or sending the data to a specialist data destruction company. You might consider data destruction if you feel the data on the device is of such importance that you would not want to risk the data ever being recovered by someone else. Can I get someone else to securely delete data from my equipment?Yes. If you are not confident in performing the deletion yourself you can get assistance from a professional who has experience in this area.
Data erasure (sometimes referred to as data clearing, data wiping, or data destruction) is a software-based method of overwriting the data that aims to completely destroy all electronic data residing on a hard disk drive or other digital media by using zeros and ones to overwrite data onto all sectors of the device in an irreversible process. By overwriting the data on the storage device, the data is rendered irrecoverable and achieves data sanitization.
Ideally, software designed for data erasure should:
Permanent data erasure goes beyond basic file deletion commands, which only remove direct pointers to the data disk sectors and make the data recovery possible with common software tools. Unlike degaussing and physical destruction, which render the storage media unusable, data erasure removes all information while leaving the disk operable. New flash memory-based media implementations, such as solid-state drives or USB flash drives, can cause data erasure techniques to fail allowing remnant data to be recoverable.[1] Software-based overwriting uses a software application to write a stream of zeros, ones or meaningless pseudorandom data onto all sectors of a hard disk drive. There are key differentiators between data erasure and other overwriting methods, which can leave data intact and raise the risk of data breach, identity theft or failure to achieve regulatory compliance. Many data eradication programs also provide multiple overwrites so that they support recognized government and industry standards, though a single-pass overwrite is widely considered to be sufficient for modern hard disk drives. Good software should provide verification of data removal, which is necessary for meeting certain standards.
To protect the data on lost or stolen media, some data erasure applications remotely destroy the data if the password is incorrectly entered. Data erasure tools can also target specific data on a disk for routine erasure, providing a hacking protection method that is less time-consuming than software encryption. Hardware/firmware encryption built into the drive itself or integrated controllers is a popular solution with no degradation in performance at all.
When encryption is in place, data erasure acts as a complement to crypto-shredding, or the practice of 'deleting' data by (only) deleting or overwriting the encryption keys.[2] Presently, dedicated hardware/firmware encryption solutions can perform a 256-bit full AES encryption faster than the drive electronics can write the data. Drives with this capability are known as self-encrypting drives (SEDs); they are present on most modern enterprise-level laptops and are increasingly used in the enterprise to protect the data. Changing the encryption key renders inaccessible all data stored on a SED, which is an easy and very fast method for achieving a 100% data erasure. Theft of an SED results in a physical asset loss, but the stored data is inaccessible without the decryption key that is not stored on a SED, assuming there are no effective attacks against AES or its implementation in the drive hardware.[citation needed] Information technology assets commonly hold large volumes of confidential data. Social security numbers, credit card numbers, bank details, medical history and classified information are often stored on computer hard drives or servers. These can inadvertently or intentionally make their way onto other media such as printers, USB, flash, Zip, Jaz, and REV drives. Data breachIncreased storage of sensitive data, combined with rapid technological change and the shorter lifespan of IT assets, has driven the need for permanent data erasure of electronic devices as they are retired or refurbished. Also, compromised networks and laptop theft and loss, as well as that of other portable media, are increasingly common sources of data breaches. If data erasure does not occur when a disk is retired or lost, an organization or user faces a possibility that the data will be stolen and compromised, leading to identity theft, loss of corporate reputation, threats to regulatory compliance and financial impacts. Companies spend large amounts of money to make sure their data is erased when they discard disks.[3][dubious ] High-profile incidents of data theft include:
Regulatory complianceStrict industry standards and government regulations are in place that force organizations to mitigate the risk of unauthorized exposure of confidential corporate and government data. Regulations in the United States include HIPAA (Health Insurance Portability and Accountability Act); FACTA (The Fair and Accurate Credit Transactions Act of 2003); GLB (Gramm-Leach Bliley); Sarbanes-Oxley Act (SOx); and Payment Card Industry Data Security Standards (PCI DSS) and the Data Protection Act in the United Kingdom. Failure to comply can result in fines and damage to company reputation, as well as civil and criminal liability.[citation needed] Preserving assets and the environmentData erasure offers an alternative to physical destruction and degaussing for secure removal of all the disk data. Physical destruction and degaussing destroy the digital media, requiring disposal and contributing to electronic waste while negatively impacting the carbon footprint of individuals and companies.[10] Hard drives are nearly 100% recyclable and can be collected at no charge from a variety of hard drive recyclers after they have been sanitized.[11] LimitationsData erasure may not work completely on flash based media, such as Solid State Drives and USB Flash Drives, as these devices can store remnant data which is inaccessible to the erasure technique, and data can be retrieved from the individual flash memory chips inside the device.[1] Data erasure through overwriting only works on hard drives that are functioning and writing to all sectors. Bad sectors cannot usually be overwritten, but may contain recoverable information. Bad sectors, however, may be invisible to the host system and thus to the erasing software. Disk encryption before use prevents this problem. Software-driven data erasure could also be compromised by malicious code.[12] Software-based data erasure uses a disk accessible application to write a combination of ones, zeroes and any other alpha numeric character also known as the "mask" onto each hard disk drive sector. The level of security when using software data destruction tools are increased dramatically by pre-testing hard drives for sector abnormalities and ensuring that the drive is 100% in working order. The number of wipes has become obsolete with the more recent inclusion of a "verify pass" which scans all sectors of the disk and checks against what character should be there i.e.; 1 Pass of AA has to fill every writable sector of the hard disk. This makes any more than 1 Pass an unnecessary and certainly a more damaging act especially as drives have passed the 1TB mark. Full disk overwritingWhile there are many overwriting programs, only those capable of complete data erasure offer full security by destroying the data on all areas of a hard drive. Disk overwriting programs that cannot access the entire hard drive, including hidden/locked areas like the host protected area (HPA), device configuration overlay (DCO), and remapped sectors, perform an incomplete erasure, leaving some of the data intact. By accessing the entire hard drive, data erasure eliminates the risk of data remanence.[citation needed] Data erasure can also bypass the Operating System (OS). Overwriting programs that operate through the OS will not always perform a complete erasure because they cannot modify the contents of the hard drive that are actively in use by that OS. Because of this, many data erasure programs are provided in a bootable format, where you run off of a live CD that has all of the necessary software to erase the disk.[citation needed] Hardware supportData erasure can be deployed over a network to target multiple PCs rather than having to erase each one sequentially. In contrast with DOS-based overwriting programs that may not detect all network hardware, Linux-based data erasure software supports high-end server and storage area network (SAN) environments with hardware support for Serial ATA, Serial Attached SCSI (SAS) and Fibre Channel disks and remapped sectors. It operates directly with sector sizes such as 520, 524, and 528, removing the need to first reformat back to 512 sector size. WinPE has now overtaken Linux as the environment of choice since drivers can be added with little effort. This also helps with data destruction of tablets and other handheld devices that require pure UEFI environments without hardware NIC's installed and/or are lacking UEFI network stack support. StandardsMany government and industry standards exist for software-based overwriting that removes the data. A key factor in meeting these standards is the number of times the data is overwritten. Also, some standards require a method to verify that all the data have been removed from the entire hard drive and to view the overwrite pattern. Complete data erasure should account for hidden areas, typically DCO, HPA and remapped sectors. The 1995 edition of the National Industrial Security Program Operating Manual (DoD 5220.22-M) permitted the use of overwriting techniques to sanitize some types of media by writing all addressable locations with a character, its complement, and then a random character. This provision was removed in a 2001 change to the manual and was never permitted for Top Secret media, but it is still listed as a technique by many providers of the data erasure software.[13] Data erasure software should provide the user with a validation certificate indicating that the overwriting procedure was completed properly. Data erasure software should[citation needed] also comply with requirements to erase hidden areas, provide a defects log list and list bad sectors that could not be overwritten.
Data can sometimes be recovered from a broken hard drive. However, if the platters on a hard drive are damaged, such as by drilling a hole through the drive (and the platters inside), then the data can only theoretically be recovered by bit-by-bit analysis of each platter with advanced forensic technology. Number of overwrites neededData on floppy disks can sometimes be recovered by forensic analysis even after the disks have been overwritten once with zeros (or random zeros and ones).[27] This is not the case with modern hard drives:
The e-waste centre of Agbogbloshie, Ghana. Multimillion-dollar agreements from United States security institutions such as the Defense Intelligence Agency (DIA), the Transportation Security Administration and Homeland Security have all resurfaced in Agbogbloshie.[31][32] E-waste presents a potential security threat to individuals and exporting countries. Hard drives that are not properly erased before the computer is disposed of can be reopened, exposing sensitive information. Credit card numbers, private financial data, account information and records of online transactions can be accessed by most willing individuals. Organized criminals in Ghana commonly search the drives for information to use in local scams.[31] Government contracts have been discovered on hard drives found in Agbogbloshie. Multimillion-dollar agreements from United States security institutions such as the Defense Intelligence Agency (DIA), the Transportation Security Administration and Homeland Security have all resurfaced in Agbogbloshie.[31][32]
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