2,213 research outputs found

    Secure Algorithms for SAKA Protocol in the GSM Network

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    This paper deals with the security vulnerabilities of the cryptographic algorithms A3, A8, and A5 existing in the GSM network. We review these algorithms and propose new secure algorithms named NewA3, NewA8, and NewA5 algorithms with respect to the A3, A8, and A5 algorithms. Our NewA5 algorithm is based on block ciphers, but we also propose NewA5 algorithm with Cipher Feedback, Counter, and Output Feedback modes to convert block cipher into stream cipher. However, stream cipher algorithms are slower than the block cipher algorithm. These new algorithms are proposed to use with a secure and efficient authentication and key agreement (AKA) protocol in the GSM network. The proposed architecture is secure against partition attack, narrow pipe attack, collision attack, interleaving attack, and man-in-the-middle attack. The security analysis of the proposed algorithms are discussed with respect to the cryptanalysis, brute force analysis, and operational analysis. We choose the NewA3 and NewA8 algorithms for challenge-response and key generation, respectively. Furthermore, the NewA5 is suitable for encryption as it is efficient than the existing A5/1 and A5/2 algorithms. In case when stream cipher algorithms are required to use, our new algorithms, NewA5-CTR, NewA5-CFB, and NewA5-OFB can be used for specific applications. These algorithms are completely secure and better than the existing A5/1 and A5/2 in terms of resistant to attacks

    Authentication protocol for an IoT-enabled LTE networks

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    The Evolved Packet System-based Authentication and Key Agreement (EPS-AKA) protocol of the long-term evolution (LTE) network does not support Internet of Things (IoT) objects and has several security limitations, including transmission of the object’s (user/device) identity and key set identifier in plaintext over the network, synchronization, large overhead, limited identity privacy, and security attack vulnerabilities. In this article, we propose a new secure and efficient AKA protocol for the LTE network that supports secure and efficient communications among various IoT devices as well as among the users. Analysis shows that our protocol is secure, efficient, and privacy preserved, and reduces bandwidth consumption during authentication

    An efficient parallel algorithm for the all pairs shortest path problem using processor arrays with reconfigurable bus systems

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    The all pairs shortest path problem is a class of the algebraic path problem. Many parallel algorithms for the solution of this problem appear in the literature. One of the efficient parallel algorithms on W-RAM model is given by Kucera [17]. Though efficient, algorithms written for the W-RAM model of parallel computation are too idealistic to be implemented on the current hardware. In this report we present an efficient parallel algorithm for the solution of this problem using a relatively new model of parallel computing, Processor Arrays with Reconfigurable Bus Systems. The parallel time complexity of this algorithm is O(log2 n) and processors complexity is n2 × n × n

    A constant time parallel algorithm for the triangularization of a sparse matrix using CD-PARBS

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    An algorithm for the triangularization of a matrix whose graph is a directed acyclic graph, popularly known as dag, is presented. One of the algorithms for obtaining this special form has been given by Sargent and Westerberg. Their approach is practically good but sequential in nature and cannot be parallelised easily. In this work we present a parallel algorithm which is based on the observation that, if we find the transitive closure matrix of a directed acyclic graph, count the number of entries in each row, sort them in the ascending order of their values and rank them accordingly, we get a lower triangular matrix. We show that all these operations can be done using 3-d CD- PARBS(Complete Directed PARBS) in constant time. The same approach can be used for the block cases, producing the same relabelling as produced by Tarjan’s algorithm, in constant time. To the best of our knowledge, it is the first approach to solve such problems using directed PARBS

    Direct observation of a hydrophobic bond in loop-closure of a capped (-OCH2CH2-)n oligomer in water

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    The small r variation of the probability density P(r) for end-to-end separations of a -CH2CH3 capped (-OCH2CH2-)n oligomer in water is computed to be closely similar to the CH4 ... CH4 potential of mean force under the same circumstances. Since the aqueous solution CH4 ... CH4 potential of mean force is the natural physical definition of a primitive hydrophobic bond, the present result identifies an experimentally accessible circumstance for direct observation of a hydrophobic bond which has not been observed previously because of the low solubility of CH4 in water. The physical picture is that the soluble chain molecule carries the capping groups into aqueous solution, and permits them to find one another with reasonable frequency. Comparison with the corresponding results without the solvent shows that hydration of the solute oxygen atoms swells the chain molecule globule. This supports the view that the chain molecule globule might have a secondary effect on the hydrophobic interaction which is of first interest here. The volume of the chain molecule globule is important for comparing the probabilities with and without solvent because it characterizes the local concentration of capping groups. Study of other capping groups to enable X-ray and neutron diffraction measurements of P(r) is discussed.Comment: 4 pages, 3 figure
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