Systems Security Certified Practitioner – SSCP – Question0379 - Systems Security Certified Practitioner

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.

Correct 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).