Physical Security Key

A physical security key is a physical device used for two-factor authentication (2FA) that often comes in the form of a USB security key. By requiring a physical device to be present and often interacted with, physical security keys significantly reduce the risk of unauthorized access, even if a user's password is compromised. Just as 2FA provides an additional layer of protection beyond traditional username and password combinations, using a physical security key strengthens two-factor authentication by preventing the second factor from being intercepted or requested by an attacker.

One of the most advanced and widely recognized standards for physical security keys is FIDO2 (Fast IDentity Online 2). FIDO2 is a protocol developed by the FIDO Alliance, which aims to eliminate the need for passwords and provide a more secure and user-friendly authentication experience. FIDO2-compliant physical security keys use public key cryptography to authenticate users, enabling a passwordless authentication process that is both secure and efficient. These keys can be connected to a computer or mobile device via USB, NFC, or Bluetooth, and often require biometric authentication to verify users, adding an extra layer of security.

USB security keys are a popular choice for implementing 2FA because they are portable, easy to use, and highly secure. These keys can be inserted into a USB port on a computer or connected to a mobile device via a USB-C or Lightning port. Once connected, the user is prompted to touch the key to complete the authentication process. This method is not only more secure than traditional 2FA methods like SMS or email codes, but it also provides a faster and more convenient user experience. They are similar to hardware tokens, but more secure. Where hardware tokens generate one-time passcodes, physical security keys use cryptographic keys that are resistant to phishing attacks.