A personal identification number is a unique national identifier assigned to a person’s official record. It is used to link identity data such as name, address, and civil-status information across government and business systems. Because it can act as a stable reference point, it is often treated as confidential personal data rather than a simple account number.
In cyber security, this kind of identifier matters because it can support impersonation, account recovery abuse, and targeted phishing when combined with other leaked details. Attackers may use it to verify a victim, enrich stolen records, or correlate data from multiple sources. Defenders protect it with strict access controls, logging, encryption, and least privilege, since exposure can have lasting consequences even when no password is stolen. Monitoring for unusual lookups or bulk exports is also important, because legitimate access paths can be misused for data theft.