[Cryptography] nuclear arming codes

[Joe St Sauver]

Hi,

Peter Fairbrother commented:

#One technique I'm told is still in use is to affix glitter in random 
#patterns in clear epoxy to missile and/or warhead parts, then shine 
#lights on it from variable positions and compare the return sparkle 
#images to a known set for that patch. Very hard to forge.

And that technique was even covered by Wired, albeit with a different context:

"Don't Want Your Laptop Tampered With? Just Add Glitter Nail Polish"
http://www.wired.com/threatlevel/2013/12/better-data-security-nail-polish/

Regards,

Joe