This research article provides a comprehensive and integrative examination of security, trust, virtualization, and cryptographic enablement in multi-tenant cloud environments incorporating Field-Programmable Gate Arrays (FPGAs). Drawing on a diverse range of foundational and contemporary studies, the article synthesizes architectural, cryptographic, and policy-driven security concerns across hardware-based trust mechanisms, FPGA virtualization, secure data retrieval, cloud adoption, and zero-trust methodologies. The growing reliance on heterogeneous compute infrastructures, particularly the integration of reconfigurable hardware into cloud platforms, has intensified security challenges such as remote physical attacks, multi-tenant inference leakage, bitstream manipulation, data privacy risks, and trust management failures. The review unifies disparate areas including TrustZone-based system isolation, Trusted Platform Module (TPM) authorization, Physically Unclonable Function (PUF) protections, homomorphic encryption acceleration, multi-tenant risk vectors in reconfigurable hardware, and SaaS-level tenant isolation. It further integrates advanced cloud data-security frameworks encompassing secure attribute-based sharing, hybrid elliptic-curve cryptography, hierarchical indices for encrypted search, and secure auditing via Diffie–Hellman-based schemes. Methodologically, the research develops a conceptual synthesis that reinterprets existing findings through a multi-layered security lens grounded in zero-trust architectural principles. The results highlight persistent vulnerabilities in multi-tenant FPGA clouds, persistent governance shortcomings, inconsistencies in cryptographic enforcement models, and limitations in current virtualization stacks. It also identifies emergent opportunities, particularly in homomorphic-encryption-enabled federated learning, energy-aware distributed cloud security, and trusted FPGA provisioning for heterogeneous environments. The discussion proposes an expanded zero-trust FPGA-cloud model emphasizing continuous attestation, cryptographic binding of hardware identities, granular tenant isolation, and resilience against side-channel and remote physical manipulations. The article concludes that future secure FPGA–cloud ecosystems must be architected around hardware-anchored trust, dynamic policy-driven cryptography, and full-stack multi-tenant isolation integrated into cloud orchestration frameworks.