What is the main issue with media reuse?

A.
Degaussing

B.
Data remanence

C.
Media destruction

D.
Purging

Explanation:
The main issue with media reuse is data remanence, where residual information still resides on the media.
Data Remanence is the problem of residual information remaining on the media after erasure, which may be
subject to restoration by another user, thereby resulting in a loss of confidentiality. Diskettes, hard drives, tapes,
and any magnetic or writable media are susceptible to data remanence. Retrieving the bits and pieces of data
that have not been thoroughly removed from storage media is a common method of computer forensics, and is
often used by law enforcement personnel to preserve evidence and to construct a trail of misuse. Anytime a
storage medium is reused (and also when it is discarded), there is the potential for the media’s information to
be retrieved. Methods must be employed to properly destroy the existing data to ensure that no residual data is
available to new users. The “Orange Book” standard recommends that magnetic media be formatted seven
times before discard or reuse.
Incorrect Answers:
A: Degaussing is a method used to ensure that there is no residual data left on the media. This is not the main
issue with media reuse.
C: Media destruction as the name suggests is the destruction of media. This is not the main issue with media
reuse.
D: Purging is another method used to ensure that there is no residual data left on the media. This is not the
main issue with media reuse.

Krutz, Ronald L. and Russell Dean Vines, The CISSP Prep Guide: Mastering the CISSP and ISSEP Exams,
2nd Edition, Wiley Publishing, Indianapolis, 2004, p. 477