FEDERATED IDENTITY MANAGEMENT FOR DIGITAL TRUST: A CROSS-DOMAIN AUTHENTICATION FRAMEWORK

The growing adoption of cloud services, mobile platforms, and inter-organizational relationships has increased demands for trustworthy cross-administrative identity systems. Traditional identity and access management (IAM) solutions were built for single domain scenarios and fail to deliver consistent, secure and privacy-preserving access authentication for users requiring access to resources in separate and unrelated trust domains. This paper introduces a Cross-Domain Authentication Framework (CDAF) for federated identity management which brings together the protocol primitives of Security Assertion Markup Language (SAML), OAuth 2.0 and OpenID Connect (OIDC) and brings them under a centralized trust broker supported by a distributed trust registry. The framework proposes a dynamic trust-scoring mechanism, a policy-driven attribute exchange model, and a lightweight token-validation pipeline that will minimize authentication delays while maintaining interoperability among different identity providers. A prototype test-bed was deployed, and compared with traditional SAML, OAuth 2.0, OIDC, and Kerberos cross-realm authentication in a simulated multi-domain traffic scenario. Results show that the proposed framework is able to decrease the mean authentication latency by around 21 to 50 percent when compared with the baseline protocols and keep the trust-verification success rate above 97.5 percent even with up to sixteen participating domains. The results indicate that a centralized policy engine can be paired with a distributed, tamper evident trust ledger to provide a viable route for scalable, trusted digital identity across domains.