Data Residuals

A.

Actually the term "remanence" comes from electromagnetism, the study of the electromagnetics.Originally referred to (and still does in that field of study) the magnetic flux that remains in a magnetic circuit after an applied magnetomotive force has been removed.Absolutely no way a candidate will see anywhere near that much detail on any similar CISSP question, but having read this, a candidate won't be likely to forget it either.

It is becoming increasingly commonplace for people to buy used computer equipment, such as a hard drive, or router, and find information on the device left there by the previous owner; information they thought had been deleted.

This is a classic example of data remanence: the remains of partial or even the entire data set of digital information.

Normally, this refers to the data that remain on media after they are written over or degaussed.

Data remanence is most common in storage systems but can also occur in memory.

Specialized hardware devices known as degaussers can be used to erase data saved to magnetic media.

The measure of the amount of energy needed to reduce the magnetic field on the media to zero is known as coercivity.

It is important to make sure that the coercivity of the degausser is of sufficient strength to meet object reuse requirements when erasing data.

If a degausser is used with insufficient coercivity, then a remanence of the data will exist.

Remanence is the measure of the existing magnetic field on the media; it is the residue that remains after an object is degaussed or written over.

Data is still recoverable even when the remanence is small.

While data remanence exists, there is no assurance of safe object reuse.

Reference(s) used for this question: Hernandez CISSP, Steven (2012-12-21)

Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 4207-4210)

Auerbach Publications.

Kindle Edition.

and Hernandez CISSP, Steven (2012-12-21)

Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 19694-19699)

Auerbach Publications.

Kindle Edition.

The correct answer is A. remanence.

Remanence refers to the residual data left on a storage device or media even after it has been erased. This occurs because when data is stored on a device, it is physically written onto the storage medium in the form of magnetic or electrical charges. When data is erased, these charges are removed or reset, but some residue of the original data may still remain.

This residual data can be potentially accessed and recovered using specialized tools and techniques, which is a concern for security and privacy. Therefore, it is important to use secure methods to erase data, such as overwriting the data multiple times with random patterns or using specialized software that can securely erase the data.

Option B, "recovery," refers to the process of recovering lost or deleted data, which is not relevant to the question.

Option C, "sticky bits," refer to file system permissions that are set on files or directories to ensure that they are always executable, regardless of the user's permissions. This is not relevant to the question.

Option D, "semi-hidden," does not relate to the topic of data erasure or residual data.