ISO-TENANT: Rethinking FPGA Power Distribution Network (PDN): A Hardware Based Solution for Remote Power Side Channel Attacks in FPGA.

Although FPGAs in cloud applications facilitate customized hardware acceleration, they also introduce new security challenges that demand attention. Granting cloud users, the capability to reconfigure hardware designs after deployment may create potential vulnerabilities for malicious users, thereby jeopardizing entire cloud platforms. Multi-tenant FPGA services, where a single FPGA is divided spatially among multiple users, are highly vulnerable to such attacks such as remote power side channel attacks, Denial of Service (DoS) attacks and Fault Injection attacks. We propose a novel power distribution network for cloud FPGA security using physical CMOS-based galvanic isolation. In this architecture, each tenant is isolated spatially, providing protection against voltage spikes, ground loops, and electrical noise, the key premises of remote power side-channel attacks. The isolation technique is carried out by using reconfigurable MoM (Metal-over-Metal) capacitors and switch banks, along with Power Management and Configuration Controller Unit. By implementing a Custom Configuration Memory (CCM), we aim to provide a dynamic and customizable solution that allows FPGA designers to selectively interconnect or isolate groups of Configurable Logic Blocks (CLBs). This approach involves the formation of distinct regions within the FPGA, each capable of sourcing power either from a dedicated CMOS isolation power supply or the standard FPGA voltage power supply. Our approach, leveraging physical isolation, can successfully prevent such attacks and can be established as the first line of defense for cloud FPGA security.