The Mathematics of Personal Identification Numbers (PINs)
Unlike alphanumeric passwords that protect remote web accounts, PINs are almost exclusively used for physically throttled devices: payment cards at point-of-sale terminals, phone biometric backups, and door access locks.
Because ATMs and smartphones lock after 3 to 10 incorrect attempts, an adversary cannot execute high-speed brute force. Instead, attackers rely on common human psychological defaults:
- Common Pitfalls:
1234,0000,1111, and birth years (e.g.1992,2004) account for over 25% of all stolen cards successfully drained. - Unbiased Defense: Generating a truly random PIN using hardware CSPRNG eliminates predictable patterns entirely, forcing an attacker to face flat 1-in-1,000,000 odds on a 6-digit passcode.