History has taught us: never underestimate the amount of money, time, and effort someone will expend to thwart a security system. It's always better to assume the worst. Assume your adversaries are better than they are. Assume science and technology will soon be able to do things they cannot yet. Give yourself a margin for error. Give yourself more security than you need today. When the unexpected happens, you'll be glad you did.

Computer security can simply be protecting your equipment and files from disgruntled employees, spies, and anything that goes bump in the night, but there is much more. Computer security helps ensure that your computers, networks, and peripherals work as expected all the time, and that your data is safe in the event of hard disk crash or a power failure resulting from an electrical storm. Computer security also makes sure no damage is done to your data and that no one is able to read it unless you want them to.

Anyone, from the most clueless amateur to the best cryptographer, can create an algorithm that he himself can't break.

Security is a process, not a product.

People don't understand computers. Computers are magical boxes that do things. People believe what computers tell them.

Why is it that we all - myself included - believe these stories? Why are we so quick to assume that the TSA is a bunch of jack-booted thugs, officious and arbitrary and drunk with power? It's because everything seems so arbitrary, because there's no accountability or transparency in the DHS.

I tell people: if it's in the news, don't worry about it, because by definition, news is something that almost never happens.