SCIM (System for Cross-domain Identity Management) is an open protocol that standardizes user identity management and synchronization across systems using TLS encryption and authorization mechanisms. It provides a core schema for representing users and groups data, as well as RESTful API endpoints for creating, retrieving, updating, and deleting user identities. SCIM enhances security by automating user provisioning and deprovisioning, supporting role-based access control (RBAC) via Groups, and providing audit trails. While SCIM does not handle authentication, it can be used alongside authorization protocols like OAuth 2.0 for an extra layer of security.