From the man who brought us Pretty Good Privacy…
“No data security system is impenetrable. …You have to ask yourself if the information you are trying to protect is more valuable to your attacker than the cost of the attack. This should lead you to protect yourself from the cheapest attacks, while not worrying about the more expensive ones.”
This white paper was my first real encounter with cryptography back when it was considered a munition by the federal government. Zimmermann got into significant trouble when someone distributed his PGP code on the Internet. Here is his story of why he developed PGP in the first place and his subsequent Senate testimony.
