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.

The whole notion of passwords is based on an oxymoron. The idea is to have a random string that is easy to remember. Unfortunately, if it's easy to remember, it's something nonrandom like 'Susan.' And if it's random, like 'r7U2*Qnp,' then it's not easy to remember.

Surveillance of power is one of the most important ways to ensure that power does not abuse its status. But, of course, power does not like to be watched.

When a big company lays you off, they often give you a year's salary to 'go pursue a dream.' If you're stupid, you panic and get another job. If you're smart, you take the money and use the time to figure out what you want to do next.

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

The very definition of news is something that hardly ever happens. If an incident is in the news, we shouldn't worry about it. It's when something is so common that its no longer news - car crashes, domestic violence - that we should worry.