Layer 5: Identity and Access Management in the Zero Trust Era

IAM is a key part of modern cybersecurity. It changes how we protect ourselves by making identity the main trust anchor instead of using traditional perimeter-based models. This chapter presents a cost-effective IAM framework that uses open-source tools like Keycloak, FreeIPA, and Open Policy Agent (OPA) to give small and medium-sized businesses (SMEs), healthcare organizations, and public sector organizations enterprise-level authentication, authorization, and policy enforcement. The framework uses multi-factor authentication, adaptive risk-based access, and policy-as-code mechanisms to make sure that IAM follows Zero Trust principles and enforces least-privilege access. A healthcare-focused case study illustrates the practical implementation of Keycloak in safeguarding access to hospital portals, third-party clinical applications, and electronic health records. The chapter emphasizes IAM not merely as a technical safeguard but also as a strategic facilitator of regulatory compliance, operational resilience, and enduring multi-tier cyber defense.