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In recent decades, due to the emerging requirements of computation acceleration, cloud FPGAs have become popular in public clouds. Major cloud service providers, e.g. AWS and Microsoft Azure have provided FPGA computing resources in their infrastructure and have enabled users to design and deploy their own accelerators on these FPGAs. Multi-tenancy FPGAs, where multiple users can share the same FPGA fabric with certain types of isolation to improve resource efficiency, have already been proved feasible. However, this also raises security concerns. Various types of side-channel attacks targeting multi-tenancy FPGAs have been proposed and validated. The awareness of security vulnerabilities in the cloud has motivated cloud providers to take action to enhance the security of their cloud environments. In FPGA security research papers, researchers always perform attacks under the assumption that attackers successfully co-locate with victims and are aware of the existence of victims on the same FPGA board. However, the way to reach this point, i.e., how attack- ers secretly obtain information regarding accelerators on the same fabric, is constantly ignored despite the fact that it is non-trivial and important for attackers. In this paper, we present a novel finger- printing attack to gain the types of co-located FPGA accelerators. We utilize a seemingly non-malicious benchmark accelerator to sniff the communication link and collect performance traces of the FPGA-host communication link. By analyzing these traces, we are able to achieve high classification accuracy for fingerprinting co-located accelerators, which proves that attackers can use our method to perform cloud FPGA accelerator fingerprinting with a high success rate. As far as we know, this is the first paper targeting multi-tenant FPGA accelerator fingerprinting with the communica- tion side-channel. 

Modern semiconductor manufacturing often leverages a fabless model in which design and fabrication are partitioned. This has led to a large body of work attempting to secure designs sent to an untrusted third party through obfuscation methods. On the other hand, efficient de-obfuscation attacks have been proposed, such as Boolean Satisfiability attacks (SAT attacks). However, there is a lack of frameworks to validate the security and functionality of obfuscated designs. Additionally, unconventional obfuscated design flows, which vary from one obfuscation to another, have been key impending factors in realizing logic locking as a mainstream approach for securing designs. In this work, we address these two issues for Lookup Table-based obfuscation. We study both Volatile and Non-volatile versions of LUT-based obfuscation and develop a framework to validate SAT runtime using machine learning. We can achieve unparallel SAT-resiliency using LUT-based obfuscation while incurring 7% area and less than 1% power overheads. Following this, we discuss and implement a validation flow for obfuscated designs. We then fabricate a chip consisting of several benchmark designs and a RISC-V CPU in TSMC 65nm for post functionality validation. We show that the design flow and SAT-runtime validation can easily integrate LUT-based obfuscation into existing CAD tools while adding minimal verification overhead. Finally, we justify SAT-resilient LUT-based obfuscation as a promising candidate for securing designs. 

Maximizing profits while minimizing risk in a technologically advanced silicon industry has motivated the globalization of the fabrication process and electronic hardware supply chain. However, with the increasing magnitude of successful hardware attacks, the security of many hardware IPs has been compromised. Many existing security works have focused on resolving a single vulnerability while neglecting other threats. This motivated to propose a novel approach for securing hardware IPs during the fabrication process and supply chain via logic obfuscation by utilizing emerging spin-based devices. Our proposed dynamic obfuscation approach uses reconfigurable logic and interconnects blocks (RIL-Blocks), consisting of Magnetic Random Access Memory (MRAM)-based Look Up Tables and switch boxes flexibility and resiliency against state-of-the-art SAT-based attacks and power side-channel attacks while incurring a small overhead. The proposed Scan Enabled Obfuscation circuitry obfuscates the oracle circuit’s responses and further fortifies the logic and routing obfuscation provided by the RIL-Blocks, resembling a defense-in-depth approach. The empirical evaluation of security provided by the proposed RIL-Blocks on the ISCAS benchmark and common evaluation platform (CEP) circuit shows that resiliency comes with reduced overhead while providing resiliency to various hardware security threats.