It's frustrating; terrorism is rare and largely ineffectual, yet we regularly magnify the effects of both their successes and failures by terrorizing ourselves.

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.

If someone steals your password, you can change it. But if someone steals your thumbprint, you can't get a new thumb. The failure modes are very different.

The more technological a society is, the greater the security gap is.

If the FBI parks a van bristling with cameras outside your house, you are justified in closing your blinds.

The mantra of any good security engineer is: "Security is a not a product, but a process." It's more than designing strong cryptography into a system; it's designing the entire system such that all security measures, including cryptography, work together.

A colleague once told me that the world was full of bad security systems designed by people who read Applied Cryptography