Every so often, I have the dubious pleasure of entering WEP keys in orderto get access to some wireless network around here. Invariably, theapplications treat the WEP key like a password, and has me type it in atext box where all the feedback I get is a ' * ' for each characterthat I type.

(We use WEP keys mostly as a way to keep random passers-by out. Notso random passers-by can crack the WEP key, at which point otherprecautions keep them

One of the things I see trotted out in response to potential securityissues is a suggestion that we make users change their passwordfrequently. In addition to all of the practical reasons not to do this,it's useful to ask one of the most important question in security: whatrisks does this protect against, and how big are they?

The concise answer is that it doesn't actually protect against anyfundamental risks. What it does is limit the damage done to your systemsby compromised passwords (if you