JavaScript Password Protection Articles

Synopsis: This article was brought about by a discussion in the usenet newsgroup news:comp.lang.javascript about the failings of the previous article Intelligent Password Verification. The majority of this rework is down to Peter Landgren, who took three attempts to come up with a solution for MSIE 3, but who got there in the end :)

Techniques: form, password, hidden, location, image, onError, onLoad, document.images, image source, floating frame

Synopsis: The vast majority of password protectors rely on the visitor knowing the name of the file, which is used as a password. However, if you get it wrong you get an error message saying file not found. The Intelligent Password Verifier uses a subtle approach, by first attempting to load an image file as the entered password, if the JavaScript detects that the image did not load, i.e. it was not found, then it displays a password invalid message.

Techniques: form, password, hidden, location, image, onError, onLoad, document.images, image source