I used to do something very similar to this, for around 5 years. It works fairly well, but I've moved away from it largely because: There are always exceptions that won't work (you can't have one scheme that both satisfies "you must have one special character" and "you cannot have any special characters"), and it also doesn't let you change your password for a site. I was able to come up with something that worked in 95% of the cases, it was the 5% that got me to stop using it.