Functional Encryption of Floating-Point ALU Using Weighted Logic Locking for Enhanced Security

Abstract

Today, almost all devices are manufactured with an arithmetic and logic unit. Floating-point ALU is used for performing various fundamental operations. It is preferred over other ALU subsystems since floating-point numbers represent both small and large numbers. Apart from this several other operations like shifting, rotating is also executed by ALU. This ALU systems can be easily manipulated and it is very difficult to prevent the unauthorized usages. The vital information is leaked out due to piracy issues. Hence, it is necessary to encrypt the ALU architecture with a logic locking block, in order to provide safety to the circuit. This paper proposes a technique called floating-point ALU with enhanced security called weighted logic locking. This technique offers high security when they are applied on the circuits. The technique can be combined to reduce the problems like key sensitization attacks. The weighted logic locking block is placed on the floating-point ALU circuit by determining the nets with maximum fault impact. The results show that there is no significant increase in the area and power overheads for the encrypted circuit from the floating-point ALU subsystem.