Comments on “A privacy preserving three-factor authentication protocol for e-health clouds”

The security provisioning of increasing healthcare data is of critical importance. The e-health clouds can be seen as a move towards an efficient management of such a big volume of healthcare data. Many schemes have been presented to bring more security and privacy along with efficiency, in the handling of data for booming e-health industry. Recently, in this connection, Jiang et al. (J Supercomput 1–24 doi: 10.1007/s11227-015-1610-x, 2016) presented a three-factor authentication protocol for e-health clouds. In this letter, we identify a serious flaw in the mutual authentication phase of the scheme, since an adversary may launch a denial-of-service attack (DoS) against the service providing server. Finally, we suggest a modification in the scheme to overcome the DoS attack.     

A secure and efficient identity-based authenticated key exchange protocol for mobile client–server networks

Recently, Chou et al. (J Supercomput 66(2): 973–988, 2013) proposed two identity-based key exchange protocols using elliptic curves for mobile environments. The first one is an two-party authentication key exchange protocol to establish a session key between a client and a remote server. The second one is an extended version for three-party setting to establish a session key between two clients with the help of a trusted server. However, this paper finds the first one vulnerable to impersonation attack and key-compromise impersonation attack, and the second one insecure against impersonation attack. To overcome the weaknesses, we propose an improved identity-based two-party authentication key exchange protocol using elliptic curves. The rigorous analysis shows that our scheme achieves more security than related protocols.     

A simple deniable authentication protocol based on the Diffie–Hellman algorithm

Deniable authentication protocol is a new authentication mechanism in secure computer communication, that not only enables an intended receiver to identify the source of a received message but also prevents a third party from identifying the source of the message. In this paper, based on the Diffie–Hellman algorithm, we propose a new simple deniable authentication protocol from a provably secure simple user authentication scheme. Compared with other deniable authentication protocols, our proposed protocol not only achieves the property of deniable authenticity, but also provides the mutual authentication between the sender and the intended receiver and the confidentiality.     

Effects of identical example–problem and problem–example pairs on learning

Examples are often an integral part of online learning environments directed at the acquisition of problem-solving skills. An unresolved issue, however, is when examples should be provided to learners. Prior research has suggested that example–problem pairs are more effective than problem–example pairs for novice learners. However, in those studies, the problem–example pairs condition may have been hindered by the fact that the examples and problems were not identical within and across pairs. The present experiment therefore employed a between-subjects design with two conditions to compare the effects of learning to solve one particular problem from studying/practicing either in an example–problem–example–problem sequence (EP condition; n = 16) or in a problem–example–problem–example sequence (PE condition; n = 16). Results show that participants in the EP condition outperformed their counterparts in the PE condition during the learning phase, but that this difference had disappeared on the test tasks after participants in the PE group had also studied the example a second time.     

A note on a problem on ω-limit sets of N–dimensional skew-product maps

In 2003, Balibrea et al. stated the problem of finding a skew-product map G on 𝕀³ holding ω _G ={0}×𝕀²=ω _G (x, y, z) for any (x, y, z)∈𝕀³, x≠0. We present a method for constructing skew-product maps F on 𝕀 ⁿ⁺¹ holding ω _F ={0}×𝕀 ⁿ =ω _F (x ₁, x ₂, …, x _n+1), (x ₁, x ₂, …, x _n+1)∈𝕀 ⁿ⁺¹, x ₁≠0.     

A pursuit–evasion problem with a constraint on the distance between objects

A trajectory pursuit–evasion problem is considered under constraints on the velocities of the counteracting objects and on the distance between them. This level of the model study brings the tactical capabilities of designed pilotless aircraft closer to the tactical capabilities of the existing piloted aircraft, which is an important problem of modern aircraft engineering. An approach that allows obtaining exact solutions in specific parametric situations is proposed.     

An efficient user authentication and key exchange protocol for mobile client–server environment

Considering the low-power computing capability of mobile devices, the security scheme design is a nontrivial challenge. The identity (ID)-based public-key system with bilinear pairings defined on elliptic curves offers a flexible approach to achieve simplifying the certificate management. In the past, many user authentication schemes with bilinear pairings have been proposed. In 2009, Goriparthi et al. also proposed a new user authentication scheme for mobile client–server environment. However, these schemes do not provide mutual authentication and key exchange between the client and the server that are necessary for mobile wireless networks. In this paper, we present a new user authentication and key exchange protocol using bilinear pairings for mobile client–server environment. As compared with the recently proposed pairing-based user authentication schemes, our protocol provides both mutual authentication and key exchange. Performance analysis is made to show that our presented protocol is well suited for mobile client–server environment. Security analysis is given to demonstrate that our proposed protocol is provably secure against previous attacks.     

A mixed hemivariational–variational problem and applications

We consider an abstract system with Lagrange multipliers which consists of a hemivariational inequality and a variational inequality. The hemivariational inequality is governed by a hemicontinuous, generalized monotone, possibly nonlinear operator as well as by a bilinear form. This bilinear form also governs the variational inequality. We are looking for a pair solution in a subset of a product of two real reflexive Banach spaces. In order to illustrate the applicability of the abstract results, two examples in terms of PDEs are delivered. Each example is related to the weak solvability of a boundary value problem arising in contact mechanics.     

A study on facility location–allocation problem in mixed environment of randomness and fuzziness

In logistics system, facility location–allocation problem, which can be used to determine the mode, the structure and the form of the whole logistics system, is a very important decision problem in the logistics network. It involves locating plants and distribution centers, and determining the best strategy for allocation the product from the plants to the distribution centers and from the distribution centers to the customers. Often uncertainty may be associated with demand, supply or various relevant costs. In many cases, randomness and fuzziness simultaneously appear in a system, in order to describe this phenomenon; we introduce the concept of hybrid variable and propose a mixed-integer programming model for random fuzzy facility location–allocation problem. By expected value and chance constraint programming technique, this model is reduced to a deterministic model. Furthermore, a priority-based genetic algorithm is designed for solving the proposed programming model and the efficacy and the efficiency of this method and algorithm are demonstrated by a numerical example. Till now, few has formulated or attacked the FLA problems in the above manner. Furthermore, the techniques illustrated in this paper can easily be applied to other SCN problems. Therefore, these techniques are the appropriate tools to tackle other supply chain network problems in realistic environments.     

A spectrum slicing method for the Kohn–Sham problem

Solving the Kohn–Sham equation, which arises in density functional theory, is a standard procedure to determine the electronic structure of atoms, molecules, and condensed matter systems. The solution of this nonlinear eigenproblem is used to predict the spatial and energetic distribution of electronic states. However, obtaining a solution for large systems is computationally intensive because the problem scales super-linearly with the number of atoms. Here we demonstrate a divide and conquer method that partitions the necessary eigenvalue spectrum into slices and computes each partial spectrum on an independent group of processors in parallel. We focus on the elements of the spectrum slicing method that are essential to its correctness and robustness such as the choice of filter polynomial, the stopping criterion for a vector iteration, and the detection of duplicate eigenpairs computed in adjacent spectral slices. Some of the more prominent aspects of developing an optimized implementation are discussed.     

A generation alternation model for user–system cooperative evolutionary computation

User?Csystem cooperative evolution (CEUS) is an evolutionary computation (EC) method to optimize quantitative and qualitative criteria. In previous work of CEUS, the whole population update is performed at every generation, and the user observes very few individuals. This paper proposes a generation alternation model designed for CEUS. The proposed model allows a user to find widely varied individuals in addition to the best individuals by replacing just one individual in a population for each generation, and consequently, contributes user??s idea generation by enhancing divergent thinking.     

A comparison of algorithms for origin–destination matrix generation on real road networks and an approximation approach

This paper considers the generation of the origin–destination (OD) matrix, basic data in any vehicle routing or traveling salesman problem. An OD matrix must be generated by calculating the shortest paths between some nodes. Candidate methods for this are repetitive use of one-to-all shortest path algorithms such as Dijkstra’s algorithm, use of all-to-all shortest path algorithms such as the Floyd–Warshall algorithm, and use of specifically designed some-to-some shortest path algorithms. This paper compares the performance of several shortest path algorithms in computing OD matrices on real road networks. Dijkstra’s algorithm with approximate bucket data structure performed the best for most of the networks tested. This paper also proposes a grouping-based algorithm for OD matrix generation. Although it is an approximation approach, it has several good characteristics: it can find the exact shortest distances for most OD pairs; it guarantees that all the calculated shortest path distance values have corresponding paths; the deviation of any distance from the corresponding true shortest distance is small; and its computation time is short.     

A new model for the preemptive earliness–tardiness scheduling problem

This paper addresses a new model for the one-machine earliness–tardiness scheduling problem where jobs can be interrupted. Some dominance rules and a lower bound are derived. A new timing algorithm is also presented and a local search algorithm based on this timing algorithm permits the computation of good feasible solutions. We experimentally compare our timing algorithm with a previously published timing algorithm. The tests show that the execution time of the new timing algorithm is significantly faster, especially for large instances. The values of the solutions are compared to the lower bound.     

A novel hybrid PSO–GWO approach for unit commitment problem

Particle swarm optimization algorithm is a inhabitant-based stochastic search procedure, which provides a populace-based search practice for getting the best solution from the problem by taking particles and moving them around in the search space and efficient for global search. Grey Wolf Optimizer is a recently developed meta-heuristic search algorithm inspired by Canis-lupus. This research paper presents solution to single-area unit commitment problem for 14-bus system, 30-bus system and 10-generating unit model using swarm-intelligence-based particle swarm optimization algorithm and a hybrid PSO–GWO algorithm. The effectiveness of proposed algorithms is compared with classical PSO, PSOLR, HPSO, hybrid PSOSQP, MPSO, IBPSO, LCA–PSO and various other evolutionary algorithms, and it is found that performance of NPSO is faster than classical PSO. However, generation cost of hybrid PSO–GWO is better than classical and novel PSO, but convergence of hybrid PSO–GWO is much slower than NPSO due to sequential computation of PSO and GWO.     

A parallel Navier–Stokes solver for the rotating flow problem

In this paper, we investigate the parallel solution of rotating internal flow problems, using the Navier–Stokes equations as proposed by Speziale and Thangam (in 1983) and Speziale (in 1985). A Runge–Kutta time-stepping scheme was applied to the equations and both sequential and message-passing implementations were developed, the latter using MPI , and were tested on a four-processor SGI Origin200 distributed, global shared memory parallel computer and on a 32-processor IBM 9076 SP/2 distributed memory parallel computer. The results show that our approach to parallelize the sequential implementation requires little effort whilst providing good results even for medium-sized problems. Copyright © 2001 John Wiley & Sons, Ltd.     

Used car salesman problem: A differential auction–barter market

We define a problem called “used car salesman problem” in which sale, purchase and barter bids can be simultaneously put forward for trading cars. A sale or a purchase bid is expressed in terms of a single car and a sale or purchase price that is required for the car. A barter bid, on the other hand, can be augmented by a differential money amount that is offered or required in addition to the cars that are to be traded. Restrictions are also allowed to be placed on sale and purchase bids. A minimum cost circulation network flow algorithm is presented which produces a solution that maximizes the profit made by the used car salesman.AMS subject classification 91B26, 90B10, 05C38     

Examining the Gramm–Leach–Bliley Act's opt-out method for protecting consumer data privacy rights on the Internet

This article involves examining the Gramm–Leach–Bliley Act's (GLBA) opt-out method in concern with protecting consumer data privacy rights online. Its purpose is to show that further regulatory measures are necessary at the federal level in order to provide better protection for consumers. To lay a foundation, it provides a background on the development of consumer data privacy rights and the collection and dissemination of personal data online and continues by exploring the practices of online merchants, credit card companies, and electronic banking in relation to the treatment of consumers’ data online. Through addressing state, federal, and self-regulatory evolvements, this article makes it apparent that the GLBA, the primary federal law protecting consumers from financial institutions use of consumer data, is insufficient and a revised legal approach for protecting consumer data online is required that is more in line with the progressive approach by the European Union and its opt-in method.     

A framework for analysing technology’s negative and positive impacts on freedom and privacy

The term ‘privacy’ refers to a cluster of values within the broad framework of human rights. Developments in information technologies have substantial negative impacts on all of the dimensions of privacy. Beyond the well-documented harm to personal data and personal communications, we are imposing on one another increasingly serious intrusions into the privacy of the physical person, of personal behaviour, and of personal experience. The survival of human society and polity are dependent on technology being brought under human control, through actions to prevent harmful applications, to resist their implementation, and to ensure robustness and resilience against their effects. Some technologies offer themselves as weapons in that battle.