Personal identification number (PIN)

What is a Personal Identification Number (PIN)? Learn how PINs work, where they’re used, and their role in secure authentication and fraud detection.

What is a personal identification number (PIN)?

A personal identification number (PIN) is a numeric password used to authenticate users, which may be combined with biometrics for added security.

Commonly associated with debit cards, online banking, and secure mobile applications, a PIN acts as a private identifier that verifies that the individual accessing a system is the rightful owner of the account or device. PINs can vary in length and complexity depending on the system or institution. They’re a foundational method of identity verification and continue to play a key role in digital security and fraud detection.

Used in combination with physical devices like ATM cards or smartphones, PINs form a fundamental but powerful component of two-factor authentication (2FA) and access control systems. Despite their simplicity, they remain relevant in today’s evolving cybersecurity landscape, especially when layered with biometric authentication.

How does a PIN work for secure access?

A PIN is a user-specific security credential restricting access to digital or physical assets. When a user enters their PIN, the system cross-references it with the one stored (usually in a hashed and encrypted form) in its backend database. If the two match, access is granted.
PINs are particularly effective when paired with a secondary security factor:

In modern digital environments, PINs often act as the first line of defense against unauthorized access, particularly for users who have yet to adopt biometric or token-based authentication.

Why are PINs important for fraud detection?

Despite the increasing use of biometrics and tokenized systems, PINs remain widely used due to their simplicity and reliability. They act as a critical defense against account takeovers, card fraud, and unauthorized access.

The PIN represents both a legacy and a complementary security method for voice authentication and fraud detection. Modern technology can integrate AI-based voice verification and device intelligence to authenticate users beyond the PIN, flagging fraudsters who may have guessed or stolen a user’s PIN but lack the right voice analysis or device profile.

Use cases for PINs in fraud detection

While easy to implement, PINs are most effective when combined with other layers of security. They can be vulnerable to shoulder surfing, phishing, or brute-force attacks, which is why multifactor authentication (MFA) and contextual security signals are vital.

Where are PINs used?

PINs are versatile and appear in a wide range of applications:

Financial services

Telecommunications + contact centers

Government services

Mobile devices + apps

IoT devices

As multi-device identity verification evolves, many scenarios are adopting voice analysis, facial recognition, or behavioral analytics, but PINs remain a backup method in many systems.

How to create a strong and secure PIN

A strong PIN is easy to remember but difficult for others to guess. As part of a broader cyber hygiene strategy, follow these tips when creating a PIN:

Some organizations now employ one-time passcodes (OTPs) sent via SMS or app for temporary authentication, reducing the risks of long-term PIN reuse.

What happens if you forget your PIN?

Forgetting a PIN can lock you out of important services, but most systems provide secure recovery or reset options:

For institutions that rely on high-trust authentication, solutions like passive authentication allow users to regain access without needing to remember or reset a PIN by verifying identity through voice and device intelligence instead.

Are PINs still secure?

PINs are still secure, but only when combined with other authentication methods.

In isolation, PINs have vulnerabilities: predictable combinations, social engineering, or phishing schemes. However, they still hold relevance when part of a layered security strategy.

Future-forward fraud detection involves:

PINs will likely evolve into dynamic, context-aware access tokens—especially in sectors like fintech, healthcare, and telecom, where user verification must be swift and unobtrusive.