Special Issue on Cyber Security

In the present cyber age, public services are getting more and more dependent on use of Information and communication technologies (ICT) day by day. A number of applications viz., Internet of Things, PDF, cloud computing and virtualization and machine to machine (M2M) system usage are sneaking deeply into our everyday life. The more we depend on ICT, the more deepens our concern about IT security or cyber security. Cyber security protects the data and integrity of assets that belong to or connect to a network. It is meant to defend those assets against all sorts of threat actors throughout the life cycle of a cyber attack. It is quite unsurprising that cyber security industry is growing at the same pace as ICT is doing

Solution of Large Sparse System of Linear Equations over GF(2) on a Multi Node Multi GPU Platform

We provide an efficient multi-node, multi-GPU implementation of the Block Wiedemann Algorithm (BWA)to find the solution of a large sparse system of linear equations over GF(2). One of the important applications ofsolving such systems arises in most integer factorization algorithms like Number Field Sieve. In this paper, wedescribe how hybrid parallelization can be adapted to speed up the most time-consuming sequence generation stage of BWA. This stage involves generating a sequence of matrix-matrix products and matrix transpose-matrix products where the matrices are very large, highly sparse, and have entries over GF(2). We describe a GPU-accelerated parallel method for the computation of these matrix-matrix products using techniques like row-wise parallel distribution of the first matrix over multi-node multi-GPU platform using MPI and CUDA and word-wise XORing of rows of the second matrix. We also describe the hybrid parallelization of matrix transpose-matrix product computation, where we divide both the matrices row-wise into equal-sized blocks using MPI. Then after a GPU-accelerated matrix transpose-matrix product generation, we combine all those blocks using MPI_BXOR operation in MPI_Reduce to obtain the result. The performance of hybrid parallelization of the sequence generation step on a hybrid cluster using multiple GPUs has been compared with parallelization on only multiple MPI processors. We have used this hybrid parallel sequence generation tool for the benchmarking of an HPC cluster. Detailed timings of the complete solution of number field sieve matrices of RSA-130, RSA-140, and RSA-170 are also compared in this paper using up to 4 NVidia V100 GPUs of a DGX station. We got a speedup of 2.8 after parallelization on 4 V100 GPUs compared to that over 1 GPU

Simple and Efficient Group Key Distribution Protocol using Matrices

Group Key Distribution (GKD) protocols are designed to distribute a group key to several users for establishing a secure communication over a public network. The central trusted authority, called the key distribution center (KDC) is in charge of distributing the group keys. For securing the communication, all the users share a common secret key in advance with KDC. In this paper, we propose a secure and efficient Group Authenticated Key Distribution (GAKD) protocol based on the simple idea of encryption in matrix rings. In this protocol, each user registers in private with the KDC, while all the other information can be transferred publicly. The scheme also supports authentication of group keys without assuming computational hard problems such as Integer Factorization Problem (IFP).The analysis of our GAKD protocol shows that the proposed protocol is resistant to reply, passive and impersonation attacks. Our construction leads to a secure, cost and computation- effective GAKD protocol

Construction of Dual Cyclic Codes over {F}_{2}[u,v]/ < u^2, v^2 - v, uv - vu > for DNA Computation

Here, we assume the construction of cyclic codes over ℜ={F}_{2}[u,v]/ &lt; u^2, v^2 - v, uv - vu &gt;. In particular, dual cyclic codes over ℜ= {F}_{2}[u]/ &lt;u^2&gt; with respect to Euclidean inner product are discussed. The cyclic dual codes over ℜ are studied with respect to DNA codes (reverse and reverse complement). Many interesting results are obtained. Some examples are also provided, which explain the main results. The GC-Content and DNA codes over ℜ are discussed. We summarise the article by giving a special DNA table

Deep Learning based Cryptanalysis of Stream Ciphers

Conventional cryptanalysis techniques necessitate an extensive analysis of non-linear functions defining the relationship of plain data, key, and corresponding cipher data. These functions have very high degree terms and make cryptanalysis work extremely difficult. The advent of deep learning algorithms along with the better and efficient computing resources has brought new opportunities to analyze cipher data in its raw form. The basic principle of designing a cipher is to introduce randomness into it, which means the absence of any patterns in cipher data. Due to this fact, the analysis of cipher data in its raw form becomes essential. Deep learning algorithms are different from conventional machine learning algorithms as the former directly work on raw data without any formal requirement of feature selection or feature extraction steps. With these facts and the assumption of the suitability of employing deep learning algorithms for cipher data, authors introduced a deep learning based method for finding biases in stream ciphers in the black-box analysis model. The proposed method has the objective to predict the occurrence of an output bit/byte at a specific location in the stream cipher generated keystream. The authors validate their method on stream cipher RC4 and its improved variant RC4A and discuss the results in detail. Further, the authors apply the method on two more stream ciphers namely Trivium and TRIAD. The proposed method can find bias in RC4 and shows the absence of this bias in its improved variant and other two ciphers. Focusing on RC4, the authors present a comparative analysis with some existing methods in terms of approach and observations and showed that their process is more straightforward and less complicated than the existing ones

Survey on SAP and its application in public-key cryptography

The concept of the semigroup action problem (SAP) was first introduced by Monico in 2002. Monico explained in his paper that the discrete logarithm problem (DLP) can be generalized to SAP. After defining the action problem in a semigroup, the concept was extended using different mathematical structures. In this paper, we discuss the concept of SAP and present a detailed survey of the work which has been done using it in public-key cryptography

Improved cryptanalysis of a ElGamal Cryptosystem Based on Matrices Over Group Rings

ElGamal cryptosystem has emerged as one of the most important construction in Public Key Cryptography (PKC) since Diffie-Hellman key exchange protocol was proposed. However, public key schemes which are based on number theoretic problems such as discrete logarithm problem (DLP) are at risk because of the evolution of quantum computers. As a result, other non-number theoretic alternatives are a dire need of entire cryptographic community

Lessons Learned from Forty Years of Subsidized Employment Programs: A Framework, Review of Models, and Recommendations for Helping Disadvantaged Workers

Subsidized employment is a promising strategy for boosting incomes and improving labor market outcomes and well-being, especially for disadvantaged workers. This report represents findings from an extensive review of evaluated or promising subsidized employment programs and models spanning four decades that target populations with serious or multiple barriers to employment in the United States. It includes a framework aimed at helping practitioners develop more innovative and effective programs by identifying key elements of program design and implementation; a review of relevant models from the past 40 years, including key findings from this research; and a set of recommendations for policymakers and practitioners for further utilization of subsidized jobs programs. The goal of this paper is to promote subsidized employment policies and programs that are likely to increase quality opportunities for individuals with serious or multiple barriers to employment, during both economic expansions and contractions. The report examines several types of programs that address in an integrated way both labor supply and demand to directly increase paid work among disadvantaged workers. The main focus is on subsidized employment programs that offer subsidies to third-party employers—public, non-profit, or for-profit—who in turn provide jobs to eligible workers. As shown in the table below, subsidized employment programs are versatile tools that, depending on factors such as the timing of the business cycle and the target population, can be adapted accordingly. The employment they provide may be temporary and countercyclical, temporary and part of a strategy to help people shift to unsubsidized employment (regardless of the macroeconomic situation), or long-term for people who need long-lasting subsidies. The experiences offered by transitional (not long-term) subsidized jobs—in terms of what they expect of employees, how well employees are compensated, and the employment and labor rules the employers must follow—conform to or closely mimic competitive employment. This report focuses particularly on the second and third strategies, though the first strategy can provide important opportunities for disadvantaged workers, even if it is deployed more broadly. In addition, this report examines some notable paid work experience programs, which may provide some compensation for training or work activities, but do not necessarily involve third-party subsidies, and may not conform to typical experiences in competitive employment. The report also reviews selected community service models, which are often not intended to mimic competitive employment but instead provide opportunities for modest work activity and nominal stipends, where appropriate. Finally, the report profiles several unsubsidized employment programs, which do not offer funding for third-party employers, as well as intensive youth-only employment programs that provide relevant lessons for subsidized employment models