Background: The rapid adoption of field-programmable gate arrays (FPGAs) within cloud infrastructures has introduced a new class of high-performance, energy-efficient accelerators for datacenter workloads. However, multi-tenant FPGA clouds create unique security, privacy, and trust challenges because hardware bitstreams, shared resources, and physical effects become new attack surfaces. This manuscript synthesizes foundational and contemporary research on FPGA cloud security and related domains — including IP protection, runtime isolation, physical unclonable functions, fault-injection attacks, operating system approaches to reconfigurable computing, and homomorphic encryption accelerators — to present an integrated conceptual framework and prescriptive design guidance for trusted multi-tenant FPGA cloud platforms. Key

contributions: (1) an expansive threat taxonomy tailored to multi-tenant FPGA clouds that links attacks to underlying physical, microarchitectural, and software vectors; (2) a layered architecture for trust that maps defensive mechanisms to threat classes, combining provenance, watermarking, PUF-based attestation, hypervisor and OS level controls, and cryptographic accelerators; (3) a detailed methodology for evaluating trustworthiness that emphasizes measurement-driven experiments and descriptive, non-mathematical analysis; and (4) an agenda for future research that prioritizes measurable isolation primitives, hardware-accelerated privacy techniques, and resilient designs against environmental and fault-based attacks.

Findings: The literature shows that heterogeneous defenses are required: IP watermarking and design fingerprints offer provenance checks but are insufficient alone (Abdel-Hamid et al., 2003); OS-centric and hypervisor approaches such as ReconOS provide strong management abstractions but must be paired with hardware attestation (Agne et al., 2014); PUFs yield compact, device-intrinsic keys appropriate for constrained devices and for bootstrapping trust in tenants and IP (Ahmed et al., 2020); fault and side-channel attacks like RAM-Jam demonstrate that environmental manipulation can violate multi-tenant isolation unless physical resource contention and environmental sensing are monitored (Alam et al., 2019); hardware accelerators for encrypted computation, including FPGA implementations for fully homomorphic encryption, offer promising paths toward preserving confidentiality even when sharing raw compute fabric (Agrawal et al., 2022).

Conclusions: A defensible multi-tenant FPGA cloud must combine provenance, device-rooted trust, runtime enforcement, and privacy-preserving computation. The paper synthesizes extant evidence to propose an integrated blueprint for secure deployment, operational monitoring, and research priorities for resilient, trustworthy FPGA clouds. All claims draw from the supplied corpus of references and directly map to the cited works.