How PALS Help Secure Nuclear Weapons

Hugh Pickens writes "The BBC reported last week that until 1998 no code or dual key system was required to arm British nuclear weapons. Bombs were armed by inserting a bicycle lock key (video) into the arming switch and turning it 90 degrees. Permissive Action Links (PALs) were introduced in the 1960s in America to prevent a mad General or pilot launching a nuclear war on their own and to control nuclear weapons that were at least partially controlled by other nations but as late as 1974, when an armed quarrel broke out between two members of NATO, Greece and Turkey, the Secretary of Defense learned that many tactical nukes were still not equipped with PALS. It has been reported that PALs have been installed on Pakistan's nuclear weapons to disarm or disable their triggering mechanism if the wrong code is entered or if the bomb is tampered with in any manner."

Comments

the PAL system was neutered by US generals

[SuperBanana]

Permissive Action Links (PALs) were introduced in the 1960s in America to prevent a mad General or pilot launching a nuclear war on their own

Wow, that glosses over reality very nicely. The codes were all zeros until the 80's, because said generals refused to implement a system that would prevent them from "hitting back".

He rightly insisted on Permissive Action Links for the US Strategic Air Command Minuteman missiles and bombs - so that they could only be armed and detonated by the the correct codes from the President or the rest of the chain of command. However, it turns out, that whilst McNamara was nominally in charge, that SAC decided to secretly order all the PAL codes to be set to eight zeros, so that there would not be any delays caused by communications problems during a nuclear war.

(From http://yorkshire-ranter.blogspot.com/2006/03/how-not-to-write-about-uk-nuclear.html)

What's hilarious is that there were extensive efforts to implement PAL securely; all sorts of tamper-proofing and obfuscation in the weapons to make it such that you'd have to have a fair bit of training to have any hope of setting one off. Roughly the equivalent of installing high-security deadbolts throughout your property, and leaving the key in the front door lock.