Anybody know how to create a password protected chest???

Hiiiiii!!!!! I'm making a security mod, and i wanted some help on how to make a password protected chest for text passwords and 4-digit passwords (2 separate blocks, not 1 that supports both) that sets a password and keeps that password every time. for example:

when it's placed, a keypad shows up and a text input. but not for typing in, just to record the numbers you've pressed. once it senses you have enters 4 numbers entered, it saves that password for every other time you open that chest. every time you open that chest, you get that same keypad but this time you don't enter numbers for the password, you enter the numbers to open the chest. same thing for the text password but a bit different obviously. any ideas???