Entering an old password to log into Facebook

Question

I recently changed my password and well ... I was very attached to the previous one. Now every I time I log in, I keep entering the old one by mistake.

Sorry! You Entered An Old Password Your password was changed from either this computer, or another computer on the same network that you are currently on, at

How many times can I enter the old password and keep getting this notice.

Or does this notice go away after a while and returns "incorrect password". For example, if I change my password every week, is Facebook keeping the last password or all passwords I have ever used and still serve this notice ?

Answer 1

What happens if you change your password again and then you enter your original password?

This will tell you whether it's just the previous password or a whole history of passwords. You'd have to keep changing the password to see how many - not that I'm advocating that you do that of course.

If they implement a scheme where your last "N" passwords have to be unique then they will need to store this information, otherwise you could just alternate between two passwords which is only marginally more secure than keeping the same password all the time.