Homomorphic Data Isolation for Hardware Trojan Protection

The interest in homomorphic encryption/decryption is increasing due to its excellent security properties and operating facilities. It allows operating on data without revealing its content. In this work, we suggest using homomorphism for Hardware Trojan protection. We implement two partial homomorphic designs based on ElGamal encryption/decryption scheme. The first design is a multiplicative homomorphic, whereas the second one is an additive homomorphic. We implement the proposed designs on a low-cost Xilinx Spartan-6 FPGA. Area utilization, delay, and power consumption are reported for both designs. Furthermore, we introduce a dual-circuit design that combines the two earlier designs using resource sharing in order to have minimum area cost. Experimental results show that our dual-circuit design saves 35% of the logic resources compared to a regular design without resource sharing. The saving in power consumption is 20%, whereas the number of cycles needed remains almost the sam

Practical byte-granular memory blacklisting using califorms

Recent rapid strides in memory safety tools and hardware have improved software quality and security. While coarse-grained memory safety has improved, achieving memory safety at the granularity of individual objects remains a challenge due to high performance overheads usually between ~1.7x-2.2x. In this paper, we present a novel idea called Califorms, and associated program observations, to obtain a low overhead security solution for practical, byte-granular memory safety. The idea we build on is called memory blacklisting, which prohibits a program from accessing certain memory regions based on program semantics. State of the art hardware-supported memory blacklisting, while much faster than software blacklisting, creates memory fragmentation (on the order of few bytes) for each use of the blacklisted location. We observe that metadata used for blacklisting can be stored in dead spaces in a program's data memory and that this metadata can be integrated into the microarchitecture by changing the cache line format. Using these observations, a Califorms based system proposed in this paper reduces the performance overheads of memory safety to ~1.02x-1.16x while providing bytegranular protection and maintaining very low hardware overheads. Moreover, the fundamental idea of storingmetadata in empty spaces and changing cache line formats can be used for other security and performance applications