Just saw this -- too bad I didn't see it when you first posted. Anyways, the idea you propose sounds like what I've done in my app which allows you to draw a geometric shape and then generates a long (SHA-256 hash-based) password for you. You can read all about it and get the code here at CP: Users Hate Passwords (We're All Users): Never Memorize a Password Again[^] I've written the app as a iphone, Android, WinForm and web app. You can try the web app at the official site (it's all client-side javascript, nothing is saved): C'YaPass : Never type a password again[^]