There are three layers of security for SPW.
See also SpeculationOnAttacks for speculation on what sort of attacks SPW may expect in the future.
If you are considering attacking this wiki to test the security, I ask that you email me (see BayleShanks for my email) and ask my permission first -- I will probably give it if you have a "tracable" email or if I know you. I do need people to help me test the security, but I also need to protect my computer as it is my personal computer with all my schoolwork on it. If there is a lot of interest in this project I will get it a dedicated server so that I don't have to worry so much, but I'd rather not spend the effort & money until needed.