[stopping]

Small correction: The PAL doesn't handle presidential authentication. It's an extra layer of security to prevent a third party from detonating a warhead should they come into physical possession of one, and is (presumably) a static code which is integral to the operation of the weapon itself. Changing it would require complete reassembly of the warhead. The presidential authentication is handled by the missile crew, and the codes rotate daily. The PAL code is fixed and kept safe in the silo, where it is only accessed and input after the presidential order has been authenticated.

[Jenk]

The presidential missile code was "00000000" throughout many years of the cold war.

https://arstechnica.com/tech-policy/2013/12/launch-code-for-...

[stopping]

I hate to say it, but that article is inaccurately reported, and I cringe every time I see it linked. It conflates the PAL codes with the presidential launch codes, which are two distinct layers of security. Even if the PAL is hard coded to all zeros, you still need presidential authorization to initiate the launch procedure.

[red_admiral]

I thought that was the PAL, not the presidential part.

Basically, engineers added a new layer of security, personnel on the ground promptly found a workaround. Nothing ever changes.