PALS and Pakistan Part One - Introduction to Permissive Action
Links
In the aftermath of September 11th, Pakistan has been thrust
into a new relationship with the United States. Questions about
domestic reaction to this relationship have given rise to fears
of Islamic fundamentalist groups compromising the security of
Pakistan's nuclear arsenal and even suggestions that the United
States should prepare for possible military action within
Pakistan to seize control over its nuclear weapons (Davidson and
Global Security Newswire). Other commentators have suggested
cooperative measures to improve the security of Pakistan's
nuclear weapons. This paper will analyze one of these proposals:
to provide Pakistan with Permissive Action Links (PALS) for
their arsenal to prevent unauthorized use.
Permissive Action Links, or PALS, are a technology integrated
into nuclear weapons to force any potential user to enter an
authorization code before the weapon can be armed (Bellovin).
They were originally developed by the United States during the
Cold War as a method of securing our systems from rogue
commanders or Soviet infiltration. Little information is in the
public record describing how PALS actually function, but the
most recent model is the CAT F, which requires a 12 digit code
for authorization (Bellovin). The system features include: a
"limited try" system that automatically uses a detonator charge
to disable the weapon if multiple incorrect codes are entered, a
remote disabling system that allows the weapon to be rendered
useless via transmission, and a multiple code system that
accepts dummy codes designed to make cracking the code more
difficult (Bellovin). The most recent pricing data for the
system is from 1984, when the CAT D version cost roughly $50,000
(Bellovin). The newest versions are directly integrated into the
weapon using a protective skin system. The system is designed so
that any damage to the skin (in an effort to remove or bypass
the PAL) would permanently disable the bomb (Bellovin). These
features combined mean that any group that was able to obtain
one of Pakistan's weapons would encounter great difficulty
arming or using the device.