I am reading through the report of a Google vulnerability on The Reg and laughing. This is a wonderful demonstration of what the attackers do to your systems – they apply the unexpected. The story is always the same. When we build a system, we try to foresee the ways in which it will be used. Then the attackers come and use it in a still unexpected way. So the whole security field can be seen as an attempt to expand the expected and narrow down the unexpected. Strangely, the unexpected is always getting bigger though. And, conversely, the art of being an attacker is an art of unexpected, shrugging off the conventions and expectations and moving into the unknown.
Our task then is to do the impossible, to protect the systems from unexpected and, largely, unexpectable. We do it in a variety of ways but we have to remember that we are on the losing side of the battle, always. There is simply no way to turn all unexpected into expected. So this is the zen of security: protect the unprotectable, expect the unexpectable and keep doing it in spite of the odds.