CISSP Asset Security Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Overwriting with a single pass of zeros

  Why it's wrong here

  Overwriting with a single pass of zeros is generally considered insufficient for sensitive data destruction, as advanced forensic techniques can sometimes recover residual magnetic traces from underlying data layers. While it obscures the data from standard operating system access, specialized equipment can often reconstruct portions of the original information by detecting subtle magnetic variations. Therefore, for high-security requirements, a single pass does not meet robust sanitization standards.

• ✗

  Physical destruction by drilling

  Why it's wrong here

  Physical destruction by drilling is an inadequate method for comprehensive data destruction because it typically only damages a localized area of the hard drive platters. Significant portions of the magnetic media, containing sensitive data, can remain intact and potentially recoverable using forensic techniques to read the undamaged sectors. For complete destruction, methods ensuring the pulverization or complete obliteration of all data-bearing surfaces are required.

• ✓

  Degaussing

  Why this is correct

  Degaussing is a highly effective method for destroying data on magnetic storage media by exposing the hard drive to a powerful magnetic field that randomizes the magnetic domains on the platters. This process completely erases all data, rendering it unreadable and unrecoverable, as the original magnetic patterns that represented the data are irreversibly scrambled. It is a robust method for purging sensitive information from hard drives, ensuring complete data sanitization.

• ✗

  Cryptographic erasure

  Why it's wrong here

  Cryptographic erasure, also known as crypto-shredding, is effective only when the data on the drive has been consistently encrypted using strong algorithms. This method works by destroying or overwriting the encryption key, making the encrypted data irrecoverable even if the underlying bits remain on the drive. However, if the drive contains any unencrypted data, or if the encryption was not consistently applied, cryptographic erasure will not affect that unencrypted information, leaving it vulnerable.

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