Enforced security compliant PIN replacement

[Fire Elemental]

WM by default provides PIN and alphanumeric password for device security. However I dispise both of them. Alpha is too slow, and PIN isn't very secure. I'm on an exchange server that forces security on this device so I have to use one of them. However I was wondering if someone has made a new security option that exchange will accept? I was hoping to get, maybe, a image-password app but I haven't been able t find anything like that.