A secret combination of numbers or characters used for authentication, such as a PIN or password. Often used in compounds like 暗証番号 (PIN).
Please enter your PIN at the ATM.
This app asks for a password when it starts.
PIN; personal identification number; password number
encryption; coding; password protection
passphrase
Compound of 暗 (あん, 'dark; secret') and 証 (しょう, 'proof; evidence'), literally 'secret proof'. The term is used to refer to a confidential code or password.