PINkood

PINkood, commonly referred to as a PIN code, is a numeric secret used to authenticate a person to a system, card, or device. The PIN is intended to be known only by the user and is typically four digits long, though longer lengths may be used for enhanced security in some applications. It functions as a key to authorize transactions, unlock devices, or access secure services.

PINkood is widely used with payment cards at ATMs and point-of-sale terminals, with SIM cards in mobile networks, and to unlock devices such as smartphones and laptops. In many banking contexts, the PIN works as a personal authentication factor alongside card possession, and in some systems it is verified by secure hardware or by the issuing bank through encrypted channels. Some devices support offline PIN verification on a secure element or card reader, while others rely on online verification.

Security considerations emphasize keeping PINkood secret, not reusing the same PIN across different accounts, shielding the keypad during entry, and enabling account lockout after consecutive failed attempts. Users are advised to change PINkood periodically and to avoid easily guessed sequences. If a PINkood is forgotten or suspected to be compromised, legitimate recovery or reset procedures provided by the issuing institution should be followed, often requiring in-person verification or authentication through trusted channels.

Standards and terminology related to PINs are defined in financial and telecommunications contexts, including PIN management and PIN block formats used to protect PIN entries during transmission and verification. Variants include SIM PINs and device unlock codes, which serve similar authentication purposes in their respective ecosystems.