In a multilevel security system (MLS), the Pump is:

A.
A one-way information flow device

B.
A two-way information flow device

C.
A device that implements role-based access control

D.
Compartmented Mode Workstation (CMW)

Explanation:
The Pump (M.h. Kang, I.S. Moskowitz, APump for Rapid, Reliable, Secure Communications, The 1st
ACM Conference on Computer and Communications Security, Fairfax, VA, 1993) was developed at
the US Naval Research Laboratory (NRL). It permits information flow in one direction only, from a
lower level of security classification or sensitivity to a higher level. It is a convenient approach to
multilevel security in that it can be used to put together systems with different security levels. *
Answer “A two-way information flow device” is a distracter. * Answer “Compartmented Mode
Workstation (CMW)”, the CMW, refers to windows-based workstations that require users to work
with information at different classification levels. Thus, users may work with multiple windows with
different classification levels on their workstations. When data is attempted to be moved from one
window to another, mandatory access control policies are enforced. This prevents information of a
higher classification from being deposited to a location of lower classification. * Answer “A device
that implements role-based access control”, role-based access control, is an access control
mechanism and is now being considered for mandatory access control based on users’ roles in their
organizations.