Sharif Digital Repository

Isogeny-based cryptography is one of the promising post-quantum candidates mainly because of its smaller public key length. Due to its high computational cost, efficient implementations are significantly important. In this paper, we have proposed a high-speed FPGA implementation of the supersingular isogeny Diffie-Hellman (SIDH) and key encapsulation (SIKE). To this end, we have adapted the algorithm of finding optimal large-degree isogeny computation strategy for hardware implementations. Using this algorithm, hardware-suited strategies (HSSs) can be devised. We have also developed a tool to schedule field arithmetic operations efficiently using constraint programming. This tool enables... 

In the present study, an annular electromagnetic stirrer was used to fabricate the semi-solid slurry of AZ91 magnesium alloy under various conditions of electromagnetic intensities and times. The fabricated semi-solid slurry was injected into a step-die cavity, using a hydraulic jack with ram speed of 1 m/s. The effects of electromagnetic intensity, stirring time and step thicknesses on the microstructure evolution, shape factor, globules equivalent diameter, solid fraction and microhardness of samples were investigated. The experimental results showed that obtained optimal parameters of electromagnetic stirring were 55 (A) stirring current and 30 (s) stirring time. In this conditions, the... 

Cyber-physical systems contain networked embedded systems. Such systems may implement cryptographic algorithms for processing and/or communication. Therefore, they can be prone to side-channel attacks. Differential power analysis is one of such attacks, which is considered among the most serious threats against cryptographic devices. Various metrics have been proposed to evaluate the resistance of different implementations against these attacks. Some of these metrics need side-channel attacks to be conducted and depend on the considered power model. Due to the vast variety of proposed side-channel attacks and power models, comprehensively evaluating a design under these metrics is commonly... 

Public key cryptography lies among the most important bases of security protocols. The classic instances of these cryptosystems are no longer secure when a large-scale quantum computer emerges. These cryptosystems must be replaced by post-quantum ones, such as isogeny-based cryptographic schemes. Supersingular isogeny Diffie-Hellman (SIDH) and key encapsulation (SIKE) are two of the most important such schemes. To improve the performance of these protocols, we have designed several modular multipliers. These multipliers have been implemented for all the prime fields used in SIKE round 3, on a Virtex-7 FPGA, showing a time and area-time product improvement of up to 60.1% and 64.5%,... 

An important aspect of corrosion prediction for oil/gas wells and pipelines is to obtain a realistic estimate of the corrosion rate. Corrosion rate prediction involves developing a predictive model that utilizes commonly available operational parameters, existing lab/field data, and theoretical models to obtain realistic assessments of corrosion rates. This study presents a new model to predict corrosion rates by using artificial neural network (ANN) systems. The values of pH, velocity, temperature, and partial pressure of the CO2 are input variables of the network and the rate of corrosion has been set as the network output. Among the 718 data sets, 503 of the data were implemented to find... 

We present a pipelined Montgomery multiplier tailored for SIKE primes. The latency of this multiplier is far shorter than that of the previous work while its frequency competes with the highest-rated ones. The implementation results on a Virtex-7 FPGA show that this multiplier improves the time, the area-time product (AT), and the throughput of computing modular multiplication by at least 2.30, 1.60, and 1.36 times over SIKE primes respectively. We have also developed a CPU-like architecture to perform SIDH and SIKE using several instances of our modular multiplier. Using four multipliers on a Virtex-7 FPGA, the encapsulation and the decapsulation of SIKE can be performed at least 1.45 times... 

We present a pipelined Montgomery multiplier tailored for SIKE primes. The latency of this multiplier is far shorter than that of the previous work while its frequency competes with the highest-rated ones. The implementation results on a Virtex-7 FPGA show that this multiplier improves the time, the area-time product (AT), and the throughput of computing modular multiplication by at least 2.30, 1.60, and 1.36 times over SIKE primes respectively. We have also developed a CPU-like architecture to perform SIDH and SIKE using several instances of our modular multiplier. Using four multipliers on a Virtex-7 FPGA, the encapsulation and the decapsulation of SIKE can be performed at least 1.45 times...