Power analysis attack resilient block cipher implementation based on 1-of-4 data encoding

Side-channel attacks pose an inevitable challenge to the implementation of cryptographic algorithms, and it is important to mitigate them. This work identifies a novel data encoding technique based on 1-of-4 codes to resist differential power analysis attacks, which is the most investigated category of side-channel attacks. The four code words of the 1-of-4 codes, namely (0001, 0010, 1000, and 0100), are split into two sets: set-0 and set-1. Using a select signal, the data processed in hardware is switched between the two encoding sets alternately such that the Hamming weight and Hamming distance are equalized. As a case study, the proposed technique is validated for the NIST standard AES-128 cipher. The proposed technique resists differential power analysis performed using statistical methods, namely correlation, mutual information, difference of means, and Welch's t-test based on the Hamming weight and distance models. The experimental results show that the proposed countermeasure has an area overhead of 2.3× with no performance degradation comparatively.     

Preparation of poly(1,5 diamino naphthalene) nanobelts/nanodiscs through a "hard-soft combined templates" approach

This is the first report on the preparation of nanobelts/nanodiscs of poly(1,5-diamino naphthalene) (PDAN-P) in bulk quantities through a "hard-soft combined templates" approach. PDAN was nanostructured within the channels of MCM-41 (hard template) in the presence of beta-napthalene sulfonic acid (beta-NSA) (soft template) and further used as the seed for the bulk preparation of pure PDAN nanobelts/nanodiscs of PDAN (PDAN-P). Field emision scanning electron microscope image reveals that a typical nanobelt has a length of approximately 3 microm, with a uniform breadth of approximately 150 nm and a thickness of approximately 50 nm. UV-Visible spectrum reveals that the electronic features of PDAN-P are different from PDAN prepared by conventional method (PDAN-C). The electrochemical and interfacial characteristics of PDAN-P were evaluated by cyclic voltammetry and impedance spectroscopy and compared with PDAN-C. The current density characteristics of ITO/PDAN-P and ITO/PDAN-C were also compared. The potential for the onset of current and the current densities beyond the onset potentials were higher at ITO/PDAN-P than for ITO/PDAN-C. Results from electrochemical imedance spectroscopy informed that the ac conductivity of PDAN-P is higher than PDAN-C. Thus, PDAN-P exhibits distinctly different electronic and electrochemical characteristics as compared to PDAN-C.     

Static and stability analysis of the inner vessel of a fast breeder reactor

Liquid metal fast breeder nuclear reactors demand the usage of large sized thin shells for their reactor vessel components due to low operating pressure and high thermal load. Buckling is a very important aspect in the design of these vessels. In this article, analysis of the inner vessel of a typical 500 MWe fast breeder reactor is presented. Here, two different geometric configurations of the inner vessel are considered. One configuration is with the conical step joining the upper and the lower cylindrical portions, and the other is with the toroidal bottom joining the upper cylindrical part. The buckling strength of the vessel for both configurations are calculated and compared. Also, the effects of thermal load, initial geometric imperfection, geometric nonlinearity, etc. are investigated. The finite element method is used for analysis.     

RRTP - A Replacement Rule Theorem Prover

The Replacement Rule Theorem Prover (RRTP) is an instance-based, refutational, first-order clausal theorem prover. The prover is motivated by the idea of selectively replacing predicates by their definitions, and operates by selecting relevant instances of the input clauses. The relevant instances are grounded, if necessary, and tested for unsatisfiability by using a fast propositional calculus decision procedure.     

Novel Power-Aware Optimization Methodology and Efficient Task Scheduling Algorithm

The performance of central processing units (CPUs) can be enhanced by integrating multiple cores into a single chip. Cpu performance can be improved by allocating the tasks using intelligent strategy. If Small tasks wait for long time or executes for long time, then CPU consumes more power. Thus, the amount of power consumed by CPUs can be reduced without increasing the frequency. Lines are used to connect cores, which are organized together to form a network called network on chips (NOCs). NOCs are mainly used in the design of processors. However, its performance can still be enhanced by reducing power consumption. The main problem lies with task scheduling, which fully utilizes the network. Here, we propose a novel random fit algorithm for NOCs based on power-aware optimization. In this algorithm, tasks that are under the same application are mapped to the neighborhoods of the same application, whereas tasks belonging to different applications are mapped to the processor cores on the basis of a series of steps. This scheduling process is performed during the run time. Experiment results show that the proposed random fit algorithm reduces the amount of power consumed and increases system performance based on effective scheduling.     

Development of torque and flux ripple minimization algorithm for direct torque control of induction motor drive

Direct torque control (DTC) is known to produce quick and robust response in AC drives. However, during steady state, notable torque and flux ripple occur. They are reflected in speed estimation, speed response and also in increased noise. This paper proposes a new control algorithm, which provides decoupled control of the torque, and flux with constant inverter switching frequency and a minimum torque and flux ripple. Compared to the other DTC methods, this algorithm is much simpler and has less mathematical operations, and can be implemented on most existing digital drive controllers. Algorithm is based on imposing the flux vector spatial orientation and rotation speed, which defines the unique solution for reference stator voltage. This paper contributes (a) Calculation of stator flux vector, torque and flux increments (b) The position of new stator flux vector determination (c) Calculation of the stator reference voltage (d) comparison of errors of different control strategies. In this paper, computer simulations and experimental results have been discussed for the proposed algorithm.     

Timoshenko beam finite element with four dof and convergence of O(h)

In situations where transverse shear deformations and rotary inertia in beams are important, elements based on the Timoshenko beam theory are useful. Among the two-noded, four DOF elements derived from the minimum total potential energy principle, the HTK. element proposed by Hughes et al. using linear displacement functions for both w and θ and the T1CC4 element proposed by Tessler et al. using quadratic displacement function for w and linear displacement function for θ are well known in the literature. The convergence of the HTK element in the thin beam situation has been too poor due to shear locking but by using selective integration this element can be shown to be equivalent to the T1CC4 element which has a rate of convergence of O(h²). In this paper a five DOF element with w and θ at the end nodes and θ at the middle node and based on the cubic displacement function for w and the quadratic displacement function for θ is first developed. Statically condensing the middle rotational DOF, the well-known (4 × 4) stiffness matrix using the φ-factor defined as φ = 12EI/kGAL² and hitherto obtained only through a flexibility approach or closed-form solution of the governing equations of the Timoshenko beam theory is derived. This element based on cubic displacement function for w has rate of convergence of O(h⁴), is completely free of shear locking and performs equally well in thin as well as thick beam situations.