I mean, Google already does this for account recovery. One of their recovery methods involves entering “the most recent password you remember” and I’m guessing on the back end also does some precision guess work related to the machine making the reset attempt. If it’s a LG phone in Fargo ND matching one you were previously logged into it’ll be more likely to let you in for example (this is pure speculation based on what I’ve witnessed people struggling to regain access to their Google accounts go through)
I think you don’t understand the point.
You enter your current password when changing your password. So it’s already there. In memory. There’s no need to persist any plain text.
In memory does not allow you to compare to multiple past passwords.
Stop, they might hear you! “Enter your previous 3 passwords”
I mean, Google already does this for account recovery. One of their recovery methods involves entering “the most recent password you remember” and I’m guessing on the back end also does some precision guess work related to the machine making the reset attempt. If it’s a LG phone in Fargo ND matching one you were previously logged into it’ll be more likely to let you in for example (this is pure speculation based on what I’ve witnessed people struggling to regain access to their Google accounts go through)