SSenStone (센스톤) is a South Korean authentication security company that develops and provides identity authentication solutions based on its proprietary OTAC (One-Time Authentication Code) technology and FIDO standards. **Core Technology:** - OTAC (One-Time Authentication Code): A unidirectional dynamic code generation algorithm that produces non-repeating, single-use codes without requiring network connectivity or server communication during code generation. - FIDO: Biometric authentication solutions based on the international FIDO standard. **Solution Categories:** *OT Auth (Operational Technology Authentication):* - Endpoint OTAC: Authentication for ICS/OT environments, including PLC systems with low computing resources. - OTAC Trusted Access Gateway: Secure gateway access for OT environments. - OTAC Auth MFA: Multi-factor authentication for OT systems. *Fin Auth (Financial Authentication):* - TAP OTAC: Card-tapping based authentication to prevent voice phishing and financial fraud. - OTAC Holderless Card: Card-based authentication without requiring a physical card holder. - OTAC Dynamic Token: Dynamic token generation for financial transactions. *IoT Auth:* - IoT Auth Platform OTAC: Authentication for IoT devices. - Smart Building OTAC, HomeNet OTAC, Connected Car OTAC, Drone OTAC: Sector-specific IoT authentication. *Access Auth:* - Identity & Access Management OTAC: IAM solutions using OTAC technology. *FIDO & mOTP Solutions:* - swIDch Auth Package and SDK for FIDO and mobile OTP authentication. **Licensing Model:** SSenStone operates under an Algorithm as a Service (AaaS) model, supplying its OTAC algorithm via licensing to fit various deployment environments.