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.

• ✗

  Cryptographic erasure by deleting the encryption key

  Why it's wrong here

  Cryptographic erasure, by deleting the encryption key, renders encrypted data inaccessible. However, this method is only effective if the entire drive was consistently and correctly encrypted from its initial use, and the key was the *only* means of access. The scenario does not specify encryption, making this approach unreliable as unencrypted data would remain fully recoverable, and even encrypted data might be vulnerable if the implementation was flawed or data was ever processed unencrypted.

• ✗

  Degaussing with a high-coercivity degausser

  Why it's wrong here

  Degaussing works by exposing magnetic media, like traditional hard disk drives (HDDs) or tapes, to a powerful magnetic field, which randomizes the magnetic domains storing data. Solid State Drives (SSDs), however, store data using electrical charges in NAND flash memory cells, not magnetic properties. Therefore, a degausser has no effect on the data stored within an SSD's flash memory, rendering this method completely ineffective for data sanitization.

• ✓

  Physical destruction such as shredding or pulverizing

  Why this is correct

  Physical destruction, through methods like shredding, pulverizing, or incineration, is the most secure and universally effective method for sanitizing Solid State Drives (SSDs). This process physically destroys the NAND flash memory chips and their individual cells, making data recovery absolutely impossible. Unlike other methods, physical destruction bypasses the complexities of wear-leveling, over-provisioning, and inaccessible blocks inherent to SSD architecture, guaranteeing complete data obliteration.

• ✗

  Overwriting with the DoD 5220.22-M 7-pass standard

  Why it's wrong here

  Overwriting standards like DoD 5220.22-M, designed for traditional magnetic media, are ineffective and unreliable for Solid State Drives (SSDs). SSDs employ wear-leveling algorithms that distribute writes across all memory blocks, meaning a specific logical block address might not correspond to the same physical block after multiple writes. Furthermore, SSDs contain inaccessible reserved blocks and over-provisioned areas that are never directly addressed by the operating system, making it impossible to guarantee that all data-containing cells have been overwritten.

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