Which of the following is not appropriate in addressing object reuse?

Which of the following is not appropriate in addressing object reuse?
A .  Degaussing magnetic tapes when they’re no longer needed.
B .  Deleting files on disk before reusing the space.
C .  Clearing memory blocks before they are allocated to a program or data.
D .  Clearing buffered pages, documents, or screens from the local memory of a terminal or printer.

View Answer

Answer: B

Explanation: Object reuse requirements, applying to systems rated TCSEC C2 and above, are used to protect files, memory, and other objects in a trusted system from being accidentally accessed by users who are not authorized to access them. Deleting files on disk merely erases file headers in a directory structure. It does not clear data from the disk surface, thus making files still recoverable. All other options involve clearing used space, preventing any unauthorized access.

Source: RUSSEL, Deborah & GANGEMI, G.T. Sr., Computer Security Basics, O’Reilly, July 1992 (page 119).