Key Hierarchy Research Articles

A key management architecture and protocols for secure smart grid communications

Providing encrypted communications among power grid components is expected to be a basic requirement of smart grid systems in the future. Here, we propose a key management architecture and associated protocols tailored to support encrypted smart grid communications. The architecture consists of two levels structured around the grid control system hierarchy. At the top level, which consist of control centers and regional coordinators, a bottom-up key structure is adopted using hash chaining and a logical key hierarchy. The lower level of the architecture consists of the regional coordinators i.e., substations and distribution systems and remote ends e.g., meters and pole-top sensors and utilizes a top-down key management approach built on an inverse element method. The proposed key management schema supports the hierarchical structure of the smart grid control mechanisms, and it takes the resource and electronic/physical security differences of the control levels into account. We define a set of protocols utilizing the architecture to provide secure unicast, multicast, and broadcast communications. Furthermore, we illustrate how the architecture is flexible enough to easily handle power grid nodes joining and leaving the system at the different levels. Lastly, we compare the proposed schema with existing ones and show that our architecture can achieve efficient key management to provide secure communications. Copyright © 2016 John Wiley & Sons, Ltd.

Diagnostics of the power oil-filled transformer equipment of thermal power plants

Problems concerning improvement of the diagnostics efficiency of the electrical facilities and functioning of the generation and distribution systems through the examples of the power oil-filled transformers, as the responsible elements referring to the electrical part of thermal power plants (TPP), were considered. Research activity is based on the fuzzy logic system allowing working both with statistical and expert information presented in the form of knowledge accumulated during operation of the power oil-filled transformer facilities. The diagnostic algorithm for various types of transformers, with the use of the intellectual estimation model of its thermal state on the basis of the key diagnostic parameters and fuzzy inference hierarchy, was developed. Criteria for taking measures allowing preventing emergencies in the electric power systems were developed. The fuzzy hierarchical model for the state assessment of the power oil-filled transformers of 110 kV, possessing high degree of credibility and setting quite strict requirements to the limits of variables of the equipment diagnostic parameters, was developed. The most frequent defects of the transformer standard elements, related with the disturbance of the isolation properties and instrumentation operation, were revealed after model testing on the real object. Presented results may be used both for the express diagnostics of the transformers state without disconnection from the power line and for more detailed analysis of the defects causes on the basis of the advanced list of the diagnostic parameters; information on those parameters may be received only after complete or partial disconnection.

TALK: Topology Aware LKH Key Management

Cryptographic key management for wireless sensor networks (WSNs) and mobile ad-hoc networks (MANETs) is a particularly challenging task, as they mostly consist of high counts of resource constrained nodes, especially when group communication and dynamic network membership capabilities are required. The logical key hierarchy (LKH) is a well-known class of protocols which aims to solve the key management problem and minimize rekeying overhead, using hierarchical structures and taking advantage of multicast communication. In this work we propose a method for obtaining LKH structures by taking into account the topology of the underlying network, leading to a further decrease in rekeying costs, in terms of packet transmissions.

Authenticated semi-quantum key distribution protocol using Bell states

This study presents the first authenticated semi-quantum key distribution (ASQKD) protocols without using authenticated classical channels. By pre-sharing a master secret key between two communicants, a sender with advanced quantum devices can transmit a working key to a receiver, who can merely perform classical operations. The idea of ASQKD enables establishment of a key hierarchy in security systems that also eases the key management problem. The proposed protocols are free from several well-known attacks

AN EFFICIENT AUTONOMOUS KEY MANAGEMENT WITH REDUCED COMMUNICATION/COMPUTATION COSTS IN MOBILE AD HOC NETWORK

A primary concern in Mobile Ad Hoc Networks (MANETs) is security. Secret sharing is an effective way to distribute a secret among n parties, where each party holds one piece of the secret. A number of ke y management schemes have been proposed for MANETs. However the secret sharing to control key hierarchy needs larger message transmission costs i n many techniques. Existing research in key management can only handle very limited number of nodes and are inefficient, insecure, or unreliable w hen the nodes increases. Here this study modifies Auton omous key management scheme is proposed to address both for security and efficiency for key management in Mobile Ad hoc Network (MANET). It also reduces communication and computational cost in Ad-Hoc Network and works for large number of nodes.

Research on Security in EMM Sublayer in TD-LTE

Security in EMM sublayer is an important part of LTE security system. This paper is developed into three part: researches on Security Mode Command and Authentication process, introduction to key hierarchy and analysis on Integrity Protection and implementation of encryption / decryption.

An Efficient Key Management Protocol for Multi-Microgrid Distribution System

This paper studies network security of the multi-microgrid distribution system (MMDS) composing of a large number of distributed power-islands. First, a hierarchical communication model for MMDS is designed . Then we analyze the security vulnerabilities. Finally, proposes an efficient secure key management protocol by combining Iolus framework and logical key hierarchy (LKH).

Performance and Rekeying Analysis of Multicast Security in LTE

Multimedia Broadcast Multicast Services (MBMS) is apoint-to-multipoint interface specification for existing and upcoming3GPP cellular networks, which is designed to provide efficient delivery ofbroadcast and multicast services, within a cell or within the core network. Target applications includemobile TV and radio broadcasting, file delivery and emergency ale rts.The main goal of this paper is to assess the performance of the Secure Multicast Overlay (SMO) and the Group Security Association (GSA). We functionally compare GSA with SMO, in terms of Keys management procedures and look up policies showing that GSA solution is appropriate in certain circumstances and SMO solution is appropriate in others. The comparison will be for different parameters and different services.Also the computational cost and storage cost for Logical Key Hierarchy (LKH) tree with and without dynamic rekeying will be calculated.

Key Management in Secure Satellite Multicast Using Key Hypergraphs

Satellite networks play an important role in today's information age because they can provide the global coverage services. Information security is an important concern in satellite multicast communications, where eavesdropping can be performed much easier than the fixed terrestrial networks. In this work, a novel multicast key management scheme based on key hypergraph for satellite networks on a predefined communication scenario is proposed. We use logical key hierarchy and distributed-logical key hierarchy as reference models for performance comparisons. It is shown that the proposed multicast key management scheme is scalable to large dynamic groups and minimizes satellite bandwidth usage.

An Efficient Group Key Management Using Code for Key Calculation for Simultaneous Join/Leave: CKCS

This paper presents an efficient group key management protocol, CKCS (Code for Key Calculation in Simultaneous join/leave) for simultaneous join/leave in secure multicast. This protocol is based on logical key hierarchy. In this protocol, when new members join the group simultaneously, server sends only the group key for those new members. Then, current members and new members calculate the necessary keys by node codes and one-way hash function. A node code is a random number which is assigned to each key to help users calculate the necessary keys. Again, at leave, the server just sends the new group key to remaining members. The results show that CKCS reduces computational and communication overhead, and also message size in simultaneous join/leave.

An Efficient Key Management Scheme for Secure Data Access Control in Wireless Broadcast Services

Wireless broadcast is an effective approach to disseminate data to a number of users. To provide secure access to data in wireless broadcast services, symmetric key - based encryption is used to ensure that only users who own the valid keys can decrypt the data. Regarding various subscriptions, an efficient key management to distribute and change keys is in great demand for access control in broadcast services. In this paper, we propose an efficient key management scheme (namely KTR) to key distribution with regarding to complex subscription options and user activities. KTR has the following advantages. First, it supports all subscription activities in wireless broadcast services. Second, in KTR, a user only needs to hold one set of keys for all subscribed programs, instead of separate sets of keys for each program. Third, KTR identifies the minimum set of keys that must be changed to ensure broadcast security and minimize the rekey cost. Our simulations show that KTR can save about 45% of communication overhead in the broadcast channel and about 50% of decryption cost for each user, compared with logical key hierarchy based approaches.

A New Secure Multicast Key Distribution Scheme Using Tabulation Method

In the present paper, we propose a new scheme for a scalable multicast key distribution scheme. The present scheme is based on the Key Management using Tabulation method of Boolean Function Simplification technique. It explores the use of batching of group membership changes to reduce the frequency, and hence the cost, of key re-distribution operations. It focuses explicitly on the issue of snowballing member removal and presents an algorithm that minimizes the number of messages required to distribute new keys to the remaining group members. The algorithm is used in conjunction with a new scalable multicast key distribution scheme which uses a set of auxiliary keys in order to improve scalability. In contrast to previous schemes which generate a fixed hierarchy of keys, the proposed scheme dynamically generates the most suitable key hierarchy by composing different keys. Our snowballing member removal uses one of the Boolean function simplification techniques called tabulation method, and outperforms all other schemes known to us in terms of message complexity. Most importantly, our technique is superior in minimizing the number of messages when multiple members leave the session in the same round.

Key Establishment Scheme for Distribution Automation System Using Logical Key Hierarchy Approach

Ethernet Passive Optical Networks (EPONs) are promising communication technologies for distribution automation system (DAS). However, EPONs have very specific security requirements, due to the broadcast character of the transmission medium. Based on the identity-based cryptography (IBC), and utilizing logical key hierarchy (LKH) approach, this paper presents an efficient key establishment scheme for distribution automation system using EPON. And the analysis results are also given in the paper.

Provably Secure Role-Based Encryption with Revocation Mechanism

Role-Based Encryption (RBE) realizes access control mechanisms over encrypted data according to the widely adopted hierarchical RBAC model. In this paper, we present a practical RBE scheme with revocation mechanism based on partial-order key hierarchy with respect to the public key infrastructure, in which each user is assigned with a unique private-key to support user identification, and each role corresponds to a public group-key that is used to encrypt data. Based on this key hierarchy structure, our RBE scheme allows a sender to directly specify a role for encrypting data, which can be decrypted by all senior roles, as well as to revoke any subgroup of users and roles. We give a full proof of security of our scheme against hierarchical collusion attacks. In contrast to the existing solutions for encrypted file systems, our scheme not only supports dynamic joining and revoking users, but also has shorter ciphertexts and constant-size decryption keys.

RiSeG: a ring based secure group communication protocol for resource-constrained wireless sensor networks

Securing group communication in wireless sensor networks has recently been extensively investigated. Many works have addressed this issue, and they have considered the grouping concept differently. In this paper, we consider a group as being a set of nodes sensing the same data type, and we alternatively propose an efficient secure group communication scheme guaranteeing secure group management and secure group key distribution. The proposed scheme (RiSeG) is based on a logical ring architecture, which permits to alleviate the group controller's task in updating the group key. The proposed scheme also provides backward and forward secrecy, addresses the node compromise attack, and gives a solution to detect and eliminate the compromised nodes. The security analysis and performance evaluation show that the proposed scheme is secure, highly efficient, and lightweight. A comparison with the logical key hierarchy is preformed to prove the rekeying process efficiency of RiSeG. Finally, we present the implementation details of RiSeG on top of TelosB sensor nodes to demonstrate its feasibility.

Challenges and trends in wireless ubiquitous computing systems

In the last decade, the Internet paradigm has been evolving toward a new frontier with the emergence of ubiquitous and pervasive systems, including wireless sensor networks, ad hoc networks, RFID systems, and wireless embedded systems. In fact, while the initial purpose of the Internet was to interconnect computers to share digital data at large scale, the current tendency is to enable ubiquitous and pervasive computing to control everything anytime and at a large scale. This new paradigm has given rise to a new generation of networked systems, commonly known as Internet-of-Things or Cyber-Physical Systems. The research community has actively investigated the underlying challenges pertaining to these systems, as they fundamentally differ from the classical problems due to their inherent constraints. This special issue presents six papers covering various topics in personal and ubiquitous computing. The first paper entitled ‘‘RiSeG: A Ring Based Secure Group Communication Protocol for Wireless Sensor Networks’’ deals with security in ubiquitous systems. The paper presents a new approach for secure group management in wireless sensor networks. The proposed approach is based on a logical ring architecture, which permits to alleviate the group controller’s task in updating the group key. The proposed scheme also provides backward and forward secrecy, addresses the node compromise attack, and gives a solution to detect and eliminate the compromised nodes. The authors evaluated their scheme in terms of storage, computation, and communication costs and compared its behavior against the Logical Key Hierarchy (LKH) scheme. It has been shown that RiSeG requires less storage cost and reduces computation and communication costs at the Group Controller as compared with LKH. The paper goes beyond theoretical work and proposes a realworld implementation, which first proved that RiSeG is applicable to WSNs and also showed that the performance results in terms of execution time, energy consumption, and memory consumption are satisfactory. The second paper entitled ‘‘Stability routing with constrained path length for improved routability in dynamic MANETs’’ addresses the problem of enhancing the routing validity in mobile wireless multi hop ad hoc networks. In proactive routing, routes are established and updated periodically and consequently loose their pertinence as time tics away from the start of their updating instants. Authors argue that routability, defined as the validity of established routes, stands among the most centric metric impacting the network efficiency. Indeed, in dynamic networks, traffic routed through invalid routes not only amounts to a waste of valuable resources but will never be delivered to its destination. In the quest of improving routability in dynamic networks, the authors considered a two-constrained QoS routing problem with one superlative constraint and one comparative constraint. In its general form, this is an NP hard problem. The authors proposed a novel exact algorithm and then instantiated the problem to solve the optimal integer weight-constrained path length A. Belghith (&) University of Manouba, Manouba, Tunisia e-mail: abdelfattah.belghith@ensi.rnu.tn

An efficient group key management protocol using code for key calculation: CKC

This paper presents a new group key management protocol, CKC (Code for Key Calculation) for secure IP multicast. In this protocol which is based on logical key hierarchy, only the group key needs to be sent to new member at join. Then, using the group key current members and the new member calculate the necessary keys by node codes and one-way hash function. A node code is a random number assigned to each node to help users calculate necessary keys. Again, at leave server just sends the new group key to the remaining members. By this key, members calculate necessary keys using node codes and one-way hash function. The security of the keys is based on one-wayness of hash function. The results show that CKC reduces computational and communication overhead, and message size largely at join without increasing them at leave.

Research on Confidentiality about Provenance Based on Logical Key Hierarchy

By analysing the security needs and the threat model of data provenance, a Key distribution algorithm based on Logical Key Hierarchy(LKH) is brought forward aiming at the confidentiality of provenance. In this paper, we make use of the LKH tree to reduce the storage of the keys for session encryption keys(SEK) of provenance records and decrease the transmission overhead of the provenance chains, which meet the requirement of compressing provenance chains, and then propose the method of dynamic expansion number of auditors that works out the problem of the auditors number dynamic changes existing in the safety requirements for confidentiality of provenance records.

A Scalable and Distributed Security Protocol for Multicast Communications

In this paper, we propose an efficient and a scalable protocol for secure multicast communication. This protocol is based on the Iolus and the logical key hierarchy protocols. It divides the whole group into several subgroups as in the Iolus protocol. Each subgroup in turn is organized in a logical key hierarchy as in the LKH protocol. This decomposition reduces the complexity for a member join or leave form O(n) to O(logm), where n is the number of the whole group members and m is the number of each subgroup members. The performance of the proposed protocol is compared with that of the Simple App., Iolus and LKH protocols. The comparison is undertaken according to the computational overhead, communication overhead, storage overhead, and message size. The results show that the proposed protocol enhances the group performance in terms of computation overhead, and communication overhead especially at the leave operation.

Secure group re-keying using key inverses

The Internet multicast capabilities have been used in enormous number of groups through the Internet. However, IP multicast does not deploy any mechanisms to secure the multicast messages in these groups. A lot of research efforts have been done to secure multicast messages. The idea behind the multicast security is to share a symmetric key between group members to encrypt/decrypt the multicast messages and to change this key after any membership change. The main re-keying problem is how to exchange the new group key between the group members in a scalable and secure way. In this paper we present a new multicast re-keying approach that is based on dividing the whole group into smaller subgroups. Each subgroup in turn is organized in a logical key hierarchy tree, and each subgroup member has the inverse key values of the other members in his subgroup in order to make the subgroup re-keying in a scalable and secure way. This decomposition, the proposed approach, which is named as Key Inverse Re-keying KIR, reduces the multicast complexity from O(n) to O(log 2m) where n is the total number of the whole group members and m is the number of members in each subgroup. The performance of KIR is compared with that of other group re-keying approaches to prove its effectiveness. The comparison is undertaken according to the computational overhead, communication overhead, storage overhead, and message size. The results show that KIR enhances the group performance in terms of computational overhead and communication overhead especially at the leave operation which represents a big problem for most of the previous group re-keying protocols.