Meta-Scanner: Detecting Fault Attacks via Scanning FPGA Designs Metadata

With the rise of the big data, processing in the cloud has become more significant. One method of accelerating applications in the cloud is to use field programmable gate arrays (FPGAs) to provide the needed acceleration for the user-specific applications. Multitenant FPGAs are a solution to increase efficiency. In this case, multiple cloud users upload their accelerator designs to the same FPGA fabric to use them in the cloud. However, multitenant FPGAs are vulnerable to low-level denial-of-service attacks that induce excessive voltage drops using the legitimate configurations. Through such attacks, the availability of the cloud resources to the nonmalicious tenants can be hugely impacted, leading to downtime and thus financial losses to the cloud service provider. In this article, we propose a tool for the offline classification to identify which FPGA designs can be malicious during operation by analysing the metadata of the bitstream generation step. We generate and test 475 FPGA designs that include 38% malicious designs. We identify and extract five relevant features out of the metadata provided from the bitstream generation step. Using ten-fold cross-validation to train a random forest classifier, we achieve an average accuracy of 97.9%. This significantly surpasses the conservative comparison with the state-of-the-art approaches, which stands at 84.0%, as our approach detects stealthy attacks undetectable by the existing methods.