What is the difference between Excelsecu PKI tokens and FIDO Security Keys?

The distinction lies in the cryptographic framework and deployment requirements. FIDO Security Keys: Designed for modern web and cloud authentication (e.g., Microsoft Entra ID). They are entirely driverless, relying on the FIDO2/WebAuthn standards supported natively by major browsers; While PKI Tokens: Designed to store X.509 digital certificates. They require middleware (such as PKCS#11 or Microsoft CSP/CNG) to interface with the operating system and are used for legacy VPN access, local Active Directory login, and S/MIME email or PDF digital signatures.