For secure communication in a distributed cooperation, generally, the data are encrypted and decrypted using a symmetric key. The process of creating, distributing, storing, deploying, and finally revoking the cryptographic keys is called key management. On the basis of the structure, usability, and complexity of the cyber-physical systems, each one of the current key management practices is suitable for a specific range of applications. However, these schemes have some drawbacks in common, such as complicated key generation and distribution process, using key storage, attacks, and traffic load. This paper proposes a key management model for establishing secure communications in the distributed industrial intelligent systems. The model is attack resistant, has high usability in real-world applications, and transforms the current customary key management workflow to enhance security and reduce weaknesses. Its main features include reduced process, intelligent attack resistance, producing dynamic keys with no additional cost, and eliminating key storage and revocation calls.

A new class of twinSudokutables (TSTs) is presented. These tables can be divided into both$s \times d$and$d \times s$subtables. They are constructed using the cyclotomic cosets of$Z_n$via two distinct vectors of cyclotomic coset elements and their Kronecker product. We prove that it is possible to generate$m$TSTs that are strongly mutually distinct (SMD), i.e., for every$0\leq i, j \leq m-1$, the$(i,j)$th entry of the tables contains different symbols. We also provide a method to construct$m$different TSTs that can be converted into twin solidSudokutables (TSSTs) as a perfect set of SMD TSSTs in order to make triplet solidSudokucubes (TSSCs). These TSSCs are symmetric cubes so that a cut from any of the six faces is a TSST. As a result, new twinSudokupuzzles (TSPs) and SMDTSPs are obtained that can be used to design new types ofSudokugames.

The Internet of Things (IoT) growth is extremely fast and it now has found its way to healthcare applications too. Many smart health gadgets and devices are helping practitioners in collecting medical information and monitoring patients. In this distributed system, information or service is sometimes shared and used by other devices. Considering the importance of health-related information and the decisions made based on it, there should be some sort of assurance on the security and quality of the services or information provided. Trust management is an efficient means of promoting application security and reliability in these cases. However, due to some limitations that are specific to IoT, traditional trust evaluation algorithms cannot be employed or do not yield satisfactory results. In this paper, evidence theory is exploited to design a decentralized service-oriented trust management model for healthcare IoT. A measure of evidence distance is used to reward well-behaving healthcare service/information providers as well as referrers and punish malicious entities. In this context-aware model, trust is estimated based on direct experiences and indirect feedbacks of recommenders. The process runs in two contexts; trust to healthcare service and trust to recommendation. When personal direct experience does not exist, trust to a source or service is estimated by applying the combinatorial laws of evidence theory and integrating indirect trust values. The proposed model is secure against bad-mouthing, good-mouthing, and on-off attacks due to its dynamic parameters and using the concept of evidence distance. Our results confirm the robustness and efficiency of this scheme.

Technology advances—such as improving processing power, battery life, and communication functionalities—contribute to making mobile devices an attractive research area. In 2008, in order to manage mobility, the Internet Engineering Task Force (IETF) developed Proxy Mobile IPv6, which is a network-based mobility management protocol to support seamless connectivity of mobile devices. This protocol can play a key role in volunteer computing paradigms as a user can seamlessly access computing resources. The procedure of user authentication is not defined in this standard; thus, many studies have been carried out to propose suitable authentication schemes. However, in the current authentication methods, with reduced latency and packet loss, some security and privacy considerations are neglected. In this study, we propose a secure and anonymous ticket-based authentication (SATA) method to protect mobile nodes against existing security and privacy issues. The proposed method reduces the overhead of handover authentication procedures using the ticket-based concept. We evaluated security and privacy strengths of the proposed method using security theorems and BAN logic.

A new method of constructing Sudoku tables (STs) (Sudoku Latin squares) is introduced by making use of individual vectors of cyclotomic cosets of Zn, and their Kronecker product. We show that, it is possible to construct m different STs of order m such that for every 0 ≤ u, v ≤ m - 1 the (u, v)-entry of these m STs is different. These STs could be considered as a perfect set of strongly mutually distinct (SMD) STs, which in turn are used to construct a solid Sudoku cube (SSC). As a result, a new version of SMD Sudoku puzzles under a new rule and condition is introduced that are interesting for Sudoku puzzles game designers.

Low decoding latency and complexity are two important requirements of channel codes used in many applications, like machine-to-machine communications. In this paper, we show how these requirements can be fulfilled by using some special quasi-cyclic low-density parity-check block codes and spatially coupled low-density parity-check convolutional codes that we denote as compact. They are defined by parity-check matrices designed according to a recent approach based on sequentially multiplied columns. This method allows obtaining codes with girth up to 12. Many numerical examples of practical codes are provided.

Techniques from coding theory are able to improve the efficiency of neuroinspired and neural associative memories by forcing some construction and constraints on the network. In this letter, the approach is to embed coding techniques into neural associative memory in order to increase their performance in the presence of partial erasures. The motivation comes from recent work by Gripon, Berrou, and coauthors, which revisited Willshaw networks and presented a neural network with interacting neurons that partitioned into clusters. The model introduced stores patterns as small-size cliques that can be retrieved in spite of partial error. We focus on improving the success of retrieval by applying two techniques: doing a local coding in each cluster and then applying a precoding step. We use a slightly different decoding scheme, which is appropriate for partial erasures and converges faster. Although the ideas of local coding and precoding are not new, the way we apply them is different. Simulations show an increase in the pattern retrieval capacity for both techniques. Moreover, we use self-dual additive codes over field [Formula: see text], which have very interesting properties and a simple-graph representation.

( t , n ) threshold secret sharing is a cryptographic mechanism to divide and disseminate information among n participants in a way that at least t ( t ≤ n ) of them should be present for the original data to be retrieved. This has practical applications in the protection of secure information against loss, destruction and theft. In this study, the authors propose a new multi‐secret sharing scheme which is based on Hermite interpolation polynomials. Using the properties of discrete logarithm over elliptic curves and bilinear maps, they have created a verifiable scheme in which there is no need for a secure channel and every participant chooses their own share. This feature does not let the dealer cheat. The proposed method is dynamic to the changes in the number and value of the secrets as well as the threshold. In addition, it has the multi‐use property which reduces the cost of secret distribution in multiple rounds of operation. The public values used in the proposed scheme are less than those of schemes providing similar features and the computations are also less complex. At the end of this study, they have compared the author's scheme with the similar ones against a comprehensive set of key features used in secret sharing.

For q an odd prime and 1≤ m ≤ q, two specific binary qm × q2parity-check matrices denoted by HP(m, q) and HI(m, q) are considered. The corresponding binary codes, CP(m, q) and CI(m, q), respectively, are called proper and improper array codes with parameters m and q. Given a parity-check matrix H representing a binary code C, let s(H) denote the stopping distance of H and d(C) be the minimum Hamming distance of C. It is known that that s(HI(m, q)) = s(HP(m, q)) = d(CI(m, q)) = d(CP(m, q)) for m ≤ 3. In this paper, we show that these equalities do not hold for all values of m and q. In particular, although s(HP(4, 7)) = d(CP(4, 7)) = 8 we have s(HI(4, 7)) = 9 and d(CI(4, 7)) = 10. It is also shown that s(HP(5,1))dCP(5, 11)) = 10 while s(HI(5,11)) = 11 and d(CI(5, 11)) = 12. This suggests that in many cases the improper array codes would perform better than the proper array codes over the AWGN and binary erasure channels. Performance results are given which confirm this claim. The combinatorial structure of the eight-element stopping sets for H(m ≥ 4,q >; 5) is also determined.

This paper presents a low-complexity recursive and systematic method to construct good well-structured low-density parity-check (LDPC) codes. The method is based on a recursive application of a partial Kronecker product operation on a given gamma x q, q ges 3 a prime, integer lattice L(gamma x q). The (n - 1)- fold product of L(gamma x q) by itself, denoted Ln(gamma x q), represents a regular quasi-cyclic (QC) LDPC code, denoted (see PDF), of high rate and girth 6. The minimum distance of (see PDF) is equal to that of the core code (see PDF) introduced by L(gamma x q). The support of the minimum weight codewords in (see PDF) are characterized by the support of the same type of codewords in (see PDF). From performance perspective the constructed codes compete with the pseudorandom LDPC codes.

A new low-complexity generating method is given for the construction of long low-density parity-check (LDPC) codes. The method is based on performing a combinatorial operation between two given configurations. Combinatorial structures such as lattices, affine and projective planes are considered as the constituent configurations. Using this method, we present several classes of well-structured four-cycle free LDPC codes of high rates most of which are quasi-cyclic. From among the main advantages of this approach, we may refer to its low-complexity property and the fact that from performance perspective the constructed codes compete with the pseudorandom LDPC codes.