Watch Out for the Inherent Vulnerabilities in Developing Multi-tenant Cloud-FPGA: Communication Protocols

As FPGAs are being deployed in the cloud infrastructure for acceleration, the technology of multi-tenant FPGA has emerged as a topic of interest. This development has drawn considerable attention to its security issues. While previous research primarily focused on the security of applications, there has been limited exploration of the vulnerabilities inherent in FPGA IPs. In our work, we examine the vulnerabilities of two widely used data transmission protocols in modern FPGAs: the Advanced eXtensible Interface (AXI) and Peripheral Component Interconnect Express (PCIe). Our experiments, conducted with commercial FPGA development kits, launched fault injection attacks through the shared power distribution network (PDN). Through non-invasive electromagnetic (EM) trace measurement, we characterize the voltage fluctuation across various attack patterns. Subsequently, we simulate real-world data transfers using two crafted datasets with different statistical characteristics. The experimental results demonstrate the unique security vulnerabilities of the current AXI and PCIe protocols in the context of a multi-tenant cloud-FPGA. In response to such vulnerability, we further propose two defense strategies: InChAXI that utilizes integrity checking for AXI-based data, and FCPCIe that employs frequency scaling for PCIe-based data. The performance evaluation demonstrates that our proposed defenses can significantly reduce the fault injections on the AXI-based data transmission by 705 times with small overheads – 0.5% in hardware footprint and 7.9% in latency, respectively. On the other hand, FCPCIe effectively prevents the fault injection attack during the PCIe-based data transmission by reducing the user clock frequency, while incurring a 10.13% overhead on data throughput.