Security and safety of FPGAS in nuclear safety systems: benefits and challenges

摘要

Field Programmable Gate Arrays (FPGAs) implementation in nuclear is becoming increasingly attractive. This paper discusses the advantages and challenges of utilising FPGAs in nuclear applications, including the improved simplicity over alternative approaches. An overview of FPGAs and the development lifecycle is given. The paper examines the current approaches to meet regulatory requirements, including Production Excellence and Independent Confidence Building Measures. The verification challenges will be discussed to include confirming the range of mature techniques and tools available covering particular FPGA requirements and where limitations have been observed. Advantages are outlined including the technology benefits, applicability for Control and Instrumentation (C&I) functionality and use in Class 1 safety systems. Standards are supporting FPGA implementations with specific guidance. However, there are known challenges, which include susceptibility to systematic errors, inclusion of third party IP cores, tool and code generators, ascertaining code implementation and the prohibitive verification tool costs. The FPGA threat model will be explained, covering the various motivations for IP theft and application compromise during the development and operational lifecycles. An overview of counter-measures is provided including, bitstream IP theft and tampering, cryptographic attacks, fault injection and physical attacks, FPGA counterfeiting and application compromise. Approaches to safety and security demonstration for Computer based systems are mature and evolving to meet improved technology; however, harmonisation of safety and security still has some way to go - potential improvements in this area are explored.