Blockchain-Based Authentication and Access Control for Secure Cloud Computing Infrastructure

Cloud computing concentrates valuable workloads behind identity services, administrative interfaces, and machine-to-machine authorization channels. Centralized access records can be difficult to reconcile across providers and may create single points of administrative failure. Blockchain-based designs offer tamper-evident policy history, shared verification, and programmable authorization, but they also introduce consensus delays, governance burdens, privacy exposure, and smart-contract risks. This narrative review evaluates an architecture in which permissioned ledger services register identity commitments and access-policy versions while sensitive attributes, credentials, and workload data remain off-chain. The paper discusses decentralized identifiers, verifiable credentials, challenge-response authentication, role- and attribute-based authorization, revocation, privacy-preserving evidence, cloud integration, and realistic security evaluation. Rather than presenting invented performance measurements, it proposes testable research questions, threat scenarios, and comparison baselines for assessing whether a ledger materially improves security over conventional identity and access management. The principal conclusion is that blockchain can improve cross-organizational auditability in some settings but is not a substitute for secure identity proofing, key custody, sound policy engineering, or operational monitoring.