The Core Difference: Built-in vs. Bring-It-With-You
Before diving into the technical weeds, let's simplify it a bit.
Passkeys: The Device-Bound Credential
Passkeys are digital credentials that replace passwords. They use the biometric sensors (Face ID, Touch ID, Windows Hello) or the PIN code of the device you are already using.
-
Where they live: They are generated and stored in the secure hardware chip of your smartphone, tablet, or computer.
-
Portability: Passkeys are primarily tied to the device they were created on. IET recommends you create a passkey on your computer. This will limit portability, and use of the passkey to just that one machine.
-
Best for: Everyday users who want seamless, phishing-resistant security without needing to buy or carry extra hardware.
YubiKeys: The Portable Hardware Key
A YubiKey is a physical security token made by Yubico. It looks like a small USB thumb drive that you can attach to your keychain.
- Where they live: The cryptographic secrets are locked completely inside the YubiKey itself. They never sync to the cloud and cannot be copied off the key.
- Portability: This is their superpower. You can take your YubiKey and plug it into any computer, phone, or tablet (via USB or NFC) to prove your identity. The security goes wherever the physical key goes, completely independent of Apple, Google, or Microsoft ecosystems.
-
Best for: High-target individuals, environments where mobile phones aren't allowed, users that don't have a smartphone or biometric capable device, or users that want the most secure option for authentication.