A strong cyber attack is capable of degrading the performance of any Information Technology (IT) or Operational Technology (OT) system. In recent cyber attacks, credential theft emerged as one of the primary vectors of gaining entry into the system. Once, an attacker has a foothold in the system, they use token manipulation techniques to elevate the privileges and access protected resources. This makes authentication and authorization a critical component for a secure and resilient cyber system. In this paper we consider the design considerations for such a secure and resilient authentication and authorization framework capable of self-adapting based on the risk scores and trust profiles. We compare this design with the existing standards such as OAuth 2.0, OpenID Connect and SAML 2.0. We then study popular threat models such as STRIDE and PASTA and summarize the resilience of the proposed architecture against common and relevant threat vectors. We call this framework Resilient Risk-based Adaptive Authentication and Authorization (RAD-AA). The proposed framework excessively increases the cost for an adversary to launch any cyber attack and provides much-needed strength to critical infrastructure.