swIDch Auth SDK by SSenStone is a next-generation user authentication development kit that utilizes One-Time Authentication Code (OTAC) technology. It enables system integrators to implement stable and efficient authentication security solutions in both communication and non-communication environments. The SDK supports FIDO biometric and simple authentication technology, allowing for both single and multi-factor authentication. It generates unique, one-time codes for each user, enhancing security by moving away from fixed-value authentication methods. The SDK provides mobile app and authentication server APIs for easy integration of security features into existing apps and enables real-time, one-time authentication for user or device identification and authentication.