Shame on you, The Economist. They say spies must be able to spy. But if spies rely on terrorists voluntarily using breakable codes, this principle doesn't count for much. All you can achieve is making the rest of us vulnerable to hackers.<p>Just two weeks ago they strongly criticised Sony for failing to use encryption to protect data and for storing passwords in a file helpfully named "Passwords". Although they don't spell out how to protect data in a retrievable fashion — nobody ever does — technology companies would essentially have to take a few cues from Sony's security policy.<p>And WHEN terrorists do again succeed, perhaps with the help of encryption, what would the new Rumsfeld's do? RSA encryption is essentially y=x^k mod n. Symmetric encryption is essentially a sequence of substitution, permutation, and addition. The whole internet is in code and compressed to have maximum entropy, like the ciphertext that results from encryption. It is, by design, indiscernible.<p>The only way to stop terrorists using encryption is to destroy the Internet itself.