In the last 20 years, computers have become a vital part of most business operations. As storage capacity and internet connection speeds increase exponentially, paperless offices are becoming commonplace and an increasing proportion of communications is occurring via computer systems. Show
But as storage capacity increases, so too does the length of time a computer can be in service, and the longer data is stored on a device, the more likely it is that errors will occur and data will be lost. Hard disk drives, also known as hard disks or hard drives, store data in sections called ësectorsà by encoding it in binary (ones and zeros) onto one or more rapidly rotating magnetised metal disks known as platters. As the platters rotate, data is written and read by a head that is attached to a motor or actuator powered arm which moves the head in arcs across the platters. Damage to a hard drive might be inflicted deliberately, by a malicious employee, for example, or it may occur as a result of overheating due to a fault elsewhere in the computer system. Overheating damages hard drives by warping the platters and causing sectors to become unreadable. Water and fire can also cause damage to the platters, actuators, motor or head, while a heavy jolt could cause the head to come into contact with the platter, resulting in damage to both. To the untrained eye, it can be difficult to spot a damaged hard drive. If your computer fails to recognise a hard drive, or freezes during boot up, the damage may not be physical, but rather logical, meaning that the problem can be solved without physically altering the drive. However, if your hard drive is making a ticking or a scratching noise, then it is very likely that it is suffering from physically damaged parts. For computer forensic experts looking to recover data from a physically damaged drive, it may be possible to recover information from the drive by replacing the damaged parts, such as the head. In such cases, an exact image of the drive contents can then be recovered and analysed. However, if the platters are badly damaged, there is sometimes no way to recover the data. If the head of a hard drive has been damaged, every revolution of the platters can cause more damage, so it is vital you do not continue to use a drive if you believe it may have suffered physical damage. That said, regardless of how serious the damage to a hard drive appears to be, it should not be passed to second hand dealers or sent to public refuse sites unless the owners are positive that the content is unrecoverable. This month is was revealed that researchers from the University of Glamorgan had recovered information regarding intercontinental missiles, bank details and NHS records on second hand hard drives from Europe, Australia and America. Such findings illustrate the importance of seeking advice from a computer forensic expert before selling or scrapping used hard drives, but they also illustrate that companies need not lose vital data. If damage is suspected, consultation with computer forensic experts can see much of the data recovered and help avoid the potential monetary and reputational expenses associated with data loss. Degaussing is the process of reducing or eliminating an unwanted magnetic field (or data) stored on tape and disk media such as computer and laptop hard drives, diskettes, reels, cassettes and cartridge tapes. When exposed to the powerful magnetic field of a degausser, the magnetic data on a tape or hard disk is neutralized, or erased. Degaussing is the guaranteed form of hard drive erasure, as such; it serves as the standard method of data destruction. Using the right degausser will guarantee that your information is no longer retrievable.
HOW DOES A DEGAUSSER ERASE HARD DRIVES AND TAPES?To understand how a degausser works, one must first understand how information is first recorded onto hard drives, tapes, reels, cassettes and other magnetic media. Magnetic media has been with us since the 1920s. Although it has seen dozens of changes over the years, the basic ideas remain the same. Magnetic tape has three basic components: a fine metal iron oxide powder, a binder and the film backing. A tape recorder works by moving the tape past a set of small metal blocks, called heads, at a steady speed. A tape recorder contains both record and playback heads. These heads are specialized electromagnets. When recording, the recording heads will create a magnetic field that alters the positioning of the fine iron oxide powder on the surface of the tape into a digital recording pattern. In turn, the playback heads read this pattern and convert it into sound, video or computer data.  Image credit: Center for Magnetic Recording Research (CMRR) Hard drives function in a similar matter, but were built for increased reliability and speed. Here, tape is exchanged for a flat, circular piece of metal, called a platter, which contains a fine coating of iron oxide or chromium dioxide. The platter spins beneath a read/write head. When small pulses of electricity are passed through a coil in the head, the surface of the platter becomes magnetized. Data is recorded using binary code, a series of 1s and 0s (magnetic pulse and reverse pulse, consecutively). A degausser erases by generating a magnetic field so powerful that it permanently removes the magnetic properties from the iron oxide or chromium dioxide coatings which erases, or randomizes, the recorded data pattern. ARE ALL DEGAUSSERS THE SAME?With so many different degausser models on the market, it’s important to know what to look for when choosing a right model for your needs as not all degaussers are created equally. Electromagnetic degaussers generate a magnetic field by charging a degaussing coil. Permanent magnet degaussers contain one or more rare earth magnets and do not require electricity to operate. Some degaussers are meant for mobile operations, while others are built for high volume. The most important aspect to consider when shopping for a degausser is its ability to erase your media. Degaussers are rated for different media based upon the degausser’s maximum magnetic field strength. The magnetic field strength of a degausser is measured in gauss, or oersteds. Tapes and hard drives also have a measurable magnetic value called coercivity, which is measured in oersteds as well. As technology has advanced through the years, coercivity ratings on tapes and hard drives has grown allowing users to store more information on said media. In turn, these higher-coercivity tapes and hard drives require advanced degaussers with more powerful magnetic fields. At Data Security, Inc., we can help you based upon your media sanitization needs. CAN I REUSE MY HARD DRIVE AFTER IT HAS BEEN DEGUASSED?No, you cannot reuse a hard drive once it has been degaussed. This is because the degaussing process not only removes all the data, but it also removes the start up files. As such, a degaussed hard drive will not boot up. CAN I REUSE MAGNETIC TAPES AFTER THEY HAVE BEEN DEGAUSSED?Most tapes are reusable after being degaussed, but a few are not. Non-reusable tapes are those which contain a servo-track, or boot-up files that are erased during the degaussing process. Non-reusable tapes include, but are not limited to:
Contact us for specific format concerns. CAN I RECYCLE DEGAUSSED MEDIA?Once a hard drive has been degaussed, it can be recycled for its precious metals. Recycling companies are often willing to purchase degaussed/damaged hard drives. Complete hard drives provide a higher recycling value than shredded hard drives. Offerings will vary by location and current market prices for precious metals, please check your local listings for a hard drive recycling vendor. WHICH DEGAUSSER IS RIGHT FOR ME?There is a lot to consider. We're happy to provide you with a FREE Needs Assessment and No Obligation Quote. Can computer forensics specialists recover deleted files from an erased disk?Computer forensics specialists cannot recover deleted files from an erased disk. With the provision of "dual criminality," a country cannot require police assistance from another country unless a suspect's activity is a crime in both countries.
What kind of data changes rapidly and may be lost when the machine that holds it is powered down?Volatile data means data that changes rapidly and may be lost when the machine that holds it is powered down. The term steganalysis refers to the determination of whether a file or communication hides other information.
What is one of the first steps in a computer forensic investigation according to the FBI?The Digital Forensic Process
First, investigators find evidence on electronic devices and save the data to a safe drive. Then, they analyze and document the information. Once it's ready, they give the digital evidence to police to help solve a crime or present it in court to help convict a criminal.
Why is physical security so critical for digital forensics labs?Physical security is one of the most important aspects of a digital forensics lab. It ensures that all employees and visitors have access to the building and their workstations while preventing malicious activity within the lab.
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