Re: Nuclear Weapons Material

>I heard a rumor (from several independent sources) which indicated that the
>firing sequences are essentially encrypted detonator timings that are passed
>through the PAL, which decrypts it but makes no value judgement about the
>timings themselves. If the timings are wrong, you get a messy squib explosion
>which will make a mess for about 100m around the detonation site, and which
>will totally destroy the weapon beyond any hope of recovery.


One would expect that there should be something in the permissive action
link that prevents a radioactive mess as well, but I have heard these
rumors too.

I always wondered if you could do dial a yield this way.  What you are
inferring is a bunch of cables of different length (delay) or the
equivalent between the firing circuit and the detonators.  The input
delay information would specify which delayed version of the detonate
signal goes down which path.


I get the impression that PAL is a little more complex than that, one
of the reputed goals is to prevent a weapon from being easily modified
to go around safeguards.  Playing with just delays can be overcome 
by characterizing delays in a dismantled weapon.

> I get the impression that PAL is a little more complex than that, one
> of the reputed goals is to prevent a weapon from being easily modified
> to go around safeguards.  Playing with just delays can be overcome 
> by characterizing delays in a dismantled weapon.

What I had heard was the the delays were implemented by varying the
chemical composition of the explosive lenses around the plutonium
core to modify their detonation rate.  This prevents replacing the
electronics to circumvent the security.

Paul J. Ste. Marie writes
> What I had heard was the the delays were implemented by varying the
> chemical composition of the explosive lenses around the plutonium
> core to modify their detonation rate.  This prevents replacing the
> electronics to circumvent the security.

This must be deliberate misinformation.  It is relatively easy to
make two explosive lenses that are exactly alike.  It is extremely
difficult to make two explosive lenses that differ by a precisely
known and constant amount.

The security in a nuclear weapon could certainly be defeated by
physically ripping out any encryption electronics and replacing
them with electronics with known and simple behavior.
-- 
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We have the right to defend ourselves and our
property, because of the kind of animals that we              James A. Donald
are.  True law derives from this right, not from
the arbitrary power of the omnipotent state.                jamesd@netcom.com

> This must be deliberate misinformation.  It is relatively easy to
> make two explosive lenses that are exactly alike.  It is extremely
> difficult to make two explosive lenses that differ by a precisely
> known and constant amount.

No one said it was easy.
 
> The security in a nuclear weapon could certainly be defeated by
> physically ripping out any encryption electronics and replacing
> them with electronics with known and simple behavior.

That was the entire point.  Having explosive lenses that aren't all
the same defeats attacks on the electronics.