Structure Of Keys Research Articles

ЦИФРОВА АВТЕНТИФІКАЦІЯ «СВІЙ-ЧУЖИЙ»

Based on a modified one-time Winternitz signature scheme, we develop a multi-time two-round group authentication protocol of the type “friend-or-foe.” The main construction is as follows. At each authentication session, members of a group sign only designated w-blocks of a random message. The verifier checks the validity of the whole Winternitz signature. Session public keys are created and sent to the verifier at the previous session. This way, they form a hash-connected blockchain. Security of the Winternitz signature and blockchain structure of public keys imply the security of the suggested protocol. A trusted third party is needed for establishing first “genesis” keys. Also, the protocol has the property “honest verifier zero knowledge”. Keywords: authentication, coalition group, digital signature, the Winternitz signature, blockchain.

Experimental study on shear performance of bond-tooth dry joints in prestressed assembled concrete beams

Assembled concrete bridges have the advantages of scale, high quality, and low requirements for the surrounding environment. However, assembled concrete beam splice joints have problems such as complex assembly and high transportation requirements. For this reason, this study proposes a large key-tooth shear key to solve the problems of low shear bearing capacity and complex collocation of conventional concrete shear keys. To study the shear capacity of the large key-tooth shear key, six large key-tooth shear key specimens were designed and tested in direct shear under monotonic vertical load. From the structure of large key-tooth concrete shear keys, the analysis focuses on the damage modes and damage criteria of large key-tooth shear keys. The effects of shear key height, key tooth depth to height ratio, number of key teeth, and concrete strength on the shear performance of assembled bridge shear keys are investigated, and the load-carrying capacity variation law of large key tooth concrete shear keys under different working conditions is explored. In addition, the parameters of the nonlinear finite element concrete material principal model and steel principal model were used to perform finite element analysis of precast assembled concrete dry joint shear keys, and the damage modes of shear keys under various working conditions were explored. Multiple linear regression equations were established to evaluate the load-carrying capacity of concrete shear keys with large key teeth and to obtain the weak surface of the structure. The three-dimensional finite element model established can well simulate the structure of large bond-tooth shear keys and more accurately assess the damaged state of shear keys for application in actual structures and design of more reasonably stressed members.

Almost Fully Secured Lattice-Based Group Signatures with Verifier-Local Revocation

An efficient member revocation mechanism is a desirable feature when group signature schemes are applied in practical scenarios. Revocation methods, such as verifier-local revocation (VLR), provide an efficient member revocation in applications of group signatures. However, VLR-group signatures rely on a weaker security notion. On the other hand, group signature schemes for static groups gain stronger security with the full-anonymity security notion. Even though an outsider sees the secret signing keys of all group members in the full-anonymity, the signer is still anonymous. Achieving the full-anonymity for VLR group signature schemes is challenging due to the structure of secret signing keys. The secret signing keys of those schemes consist of tokens, which are used to manage revocation. The reveal of tokens may destroy the anonymity of the signers. We obtain stronger security for the lattice-based VLR group signature schemes by providing a new key generation method, which outputs revocation tokens without deriving from the members’ secret signing keys. We propose a new group signature scheme from lattices with VLR, which achieves stronger security than the previous related works. To avoid signature forgeries, we suggest a new zero-knowledge proof system that requires signers to validate themselves. Moreover, we output an efficient tracing mechanism.

RETRACTED ARTICLE: Efficient data sensing with group key management for intelligent automation system by one-way key derivation in wireless networks

Over the last century, Wireless Sensor Network (WSN) has given major advances in several distinguishable fields. In addition, it has also evolved many features such as high device heterogeneity, high scale and supporting multiple applications. In WSN, Key management is employed (involves) as a significant component of network security, especially in multi-cast based applications and services. Group key management has a vital role in multi-cast secure communication with huge number of group members. Group key must always be updated dynamically to all groups in the network and keys to be redistributed currently to active members only. Consequently, a secret key called session key for a group of members is stored in key trees that are shared efficiently between them, in order to achieve secure group communication. The key trees are used to encrypt with other keys and data are transmitted to ensure security. Logical key hierarchy (LKH) is a hierarchical structure of multiple keys to provide a scalable and secrecy for group communication. This research work proposes a new hierarchical group key management (HGKM) using multiple logical key trees for dynamic groups in order to enhance the Quality of Service of the network. Among the multiple logical trees, primary tree can be selected by tree selection algorithm. In WSN, there are high numbers of members joining or leaving the group at any time, resulting with rekeying process becoming too large. This leads to degraded efficiency of tree-based key management system. Further, communication overhead of rekeying process can be mitigated by one-way key derivation method which integrates with multiple logical key trees. In this method, tree server does not need to be encrypted. Rather, it involves in sending a new key to members who are capable of derive their own keys in same way the server does. This results with a need for less number of encrypted keys for each rekeying process within the group tree. The fixed interval time is called batch time, which is applied in each rekeying process after nodes join or leave the group. The proposed approach can improve the bandwidth utilization effectively. The proposed HGKM method is implemented in Network Simulator (NS-2) environment and obtained results are compared with existing two methods such as LKH and multiple logical tree key management (MLT-KM). QOS of proposed approach is evaluated in terms of Bandwidth Efficiency.

Resource allocation mechanisms and approaches on the Internet of Things

Internet of Things (IoT) as a novel paradigm is an environment with a vast number of connected things and applications. The IoT devices are used to generate data, which transforms into useable information and provides applied resources to end-users and this process is the main goal of IoT. Therefore, one of the important subjects in the IoT is resource allocation which aims is load balancing and minimizing operational cost, and power consuming. In addition, the resources should be allocated in such a way to be a balanced efficiency that can increase the system performance, Quality of Service (QoS) and Service Level Agreement (SLA). Although the resource allocation is very important in the IoT, there is no systematic review in this field. Therefore, in this paper, a Systematic Literature Review (SLR) is provided and the resources allocation methods in the IoT and used algorithms are investigated. Different classification, including cost-aware, context-aware, efficiency-aware, load-balancing-aware, power-aware, QoS-aware, SLA-based and utilization-aware resource allocation mechanisms are organized to investigate the resource allocation techniques. We present several parameters and describe them in each category. In addition, the used parameters in different articles are evaluated and the major developments in each category are surveyed and are outlined the new challenges. Furthermore, an SLR is provided in each of these eight categories. In this paper, a structure of different technical keys in the scope of resource allocation in the IoT and its platforms are presented and the important areas for improving the resource allocation methods in the future is highlighted and the open issues about resource allocation in IoT to achieve a better utilization of this technology are focused. The future direction is useful for academic researchers that work on IoT. This study shows that an independent technique does not exist to address all issues and challenges in resource allocation for IoT.

Side-Channel Attacks on Post-Quantum Signature Schemes based on Multivariate Quadratic Equations

In this paper, we investigate the security of Rainbow and Unbalanced Oil-and-Vinegar (UOV) signature schemes based on multivariate quadratic equations, which is one of the most promising alternatives for post-quantum signature schemes, against side-channel attacks. We describe correlation power analysis (CPA) on the schemes that yield full secret key recoveries. First, we identify a secret leakage of secret affine maps S and T during matrix-vector products in signing when Rainbow is implemented with equivalent keys rather than random affine maps for optimal implementations. In this case, the simple structure of the equivalent keys leads to the retrieval of the entire secret affine map T. Next, we extend the full secret key recovery to the general case using random affine maps via a hybrid attack: after recovering S by performing CPA, we recover T by mounting algebraic key recovery attacks. We demonstrate how this leakage on Rainbow can be practically exploited on an 8-bit AVR microcontroller using CPA. Consequently, our CPA can be applied to Rainbow-like multi-layered schemes regardless of the use of the simple-structured equivalent keys and UOV-like single layer schemes with the implementations using the equivalent keys of the simple structure. This is the first result on the security of multivariate quadratic equations-based signature schemes using only CPA. Our result can be applied to Rainbow-like multi-layered schemes and UOV-like single layer schemes submitted to NIST for Post-Quantum Cryptography Standardization.

Analysis of Different Privacy Preserving Cloud Storage Frameworks

Privacy Security of data in Cloud Storage is one of the main issues. Many Frameworks and Technologies are used to preserve data security in cloud storage. [1] Proposes a framework which includes the design of data organization structure, the generation and management of keys, the treatment of change of user’s access right and dynamic operations of data, and the interaction between participants. It also design an interactive protocol and an extirpation-based key derivation algorithm, which are combined with lazy revocation, it uses multi-tree structure and symmetric encryption to form a privacy-preserving, efficient framework for cloud storage. [2] Proposes a framework which design a privacy-preserving cloud storage framework in which he designed an interaction protocol among participants, use key derivation algorithm to generate and manage keys, use both symmetric and asymmetric encryption to hide the sensitive data of users, and apply Bloom filter for cipher text retrieval. A system based on this framework is realized. This paper analyzes both the frameworks in terms of the feasibility of the frameworks, running overhead of the system and the privacy security of the frameworks.

Design and implementation of a portable TPM scheme for general-purpose trusted computing based on EFI

In today's globalized digital world, network-based, mobile, and interactive collaborations have enabled work platforms of personal computers to cross multiple geographical boundaries. The new requirements of privacy-preservation, sensitive information sharing, portability, remote attestation, and robust security create new problems in system design and implementation. There are critical demands for highly secure work platforms and security enhancing mechanisms for ensuring privacy protection, component integrity, sealed storage, and remote attestation of platforms. Trusted computing is a promising technology for enhancing the security of a platform using a trusted platform module (TPM). TPM is a tamper-resistant microcontroller designed to provide robust security capabilities for computing platforms. It typically is affixed to the motherboard with a low pin count (LPC) bus. However, it limited in that TPM cannot be used directly in current common personal computers (PCs), and TPM is not flexible and portable enough to be used in different platforms because of its interface with the PC and its certificate and key structure. For these reasons, we propose a portable trusted platform module (PTPM) scheme to build a trusted platform for the common PC based on a single cryptographic chip with a universal serial bus (USB) interface and extensible firmware interface (EFI), by which platforms can get a similar degree of security protection in general-purpose systems. We show the structure of certificates and keys, which can bind to platforms via a PTPM and provide users with portability and flexibility in different platforms while still allowing the user and platform to be protected and attested. The implementation of prototype system is described in detail and the performance of the PTPM on cryptographic operations and time-costs of the system bootstrap are evaluated and analyzed. The results of experiments show that PTPM has high performances for supporting trusted computing and it can be used flexibly and portably by the user.

Study of privacy-preserving framework for cloud storage

In order to implement privacy-preserving, efficient and secure data storage and access environment of cloud storage, the following problems must be considered: data index structure, generation and management of keys, data retrieval, treatments of change of users? access right and dynamic operations on data, and interactions among participants. To solve those problems, the interactive protocol among participants is introduced, an extirpation-based key derivation algorithm (EKDA) is designed to manage the keys, a double hashed and weighted Bloom Filter (DWBF) is proposed to retrieve the encrypted keywords, which are combined with lazy revocation, multi-tree structure, asymmetric and symmetric encryptions, which form a privacypreserving, efficient and secure framework for cloud storage. The experiment and security analysis show that EKDA can reduce the communication and storage overheads efficiently, DWBF supports ciphertext retrieval and can reduce communication, storage and computation overhead as well, and the proposed framework is privacy preserving while supporting data access efficiently.

Recent combinatorial results in the theory of relational databases

Recent results of the authors—some of which are joint with Thalheim and Seleznjev— in the area of combinatorial investigations of the relational database model are presented here. In relational databases keys—combinations of attributes uniquely identifying the records—play an important role. The structure and size of keys have been widely investigated. Here, after a short review of the earlier results, we discuss two generalizations: the (average) structure and size of keys in a random database and the concept of error-correcting keys in case of unreliable data collection.

Revisions and new taxa in New Zealand notonemouridae (insecta: Plecoptera)

Abstract A revised diagnosis of Spaniocercoides is given, 5. hudsoni Kimmins is re‐described, its larva is described for the first time, and notes on variation and ecology are added. Additions and amendments to the description of 5. cowleyi (Winterbourn), and notes on its ecology are given. S. fimbria Winterbourn is removed to Cristaperla gen. nov., and the male epiproct, the female and part of the larval exuviae are described for the first time. Omanuperla gen. nov. is erected to contain O. bruningi sp. nov. Notes on the origin and structure of ovipositors and keys to imagines and larvae are given.

SOME ASPECTS OF THE THEORY OF DICHOTOMOUS KEYS

SummaryThe structure of dichotomous keys is discussed, and some general theorems are proved concerning the number and arrangement of the taxa in any given key. The possibility is considered that the various questions in a key may occasionally be answered wrongly, the key then leading to a wrong determination. It is shown that if this possibility exists, then the probability of a right determination is almost always improved by changing the structure of the key to make it as ‘short’as possible.The possibility is also considered of adding alternative identification paths through the key (‘reticulations’), starting at points where a particularly difficult question is asked. It is shown that this practice usually improves the key in respect of the determination of certain taxa, but may often diminish the overall probability of correct determination averaged over all taxa.