Dynamic Group Communication Research Articles

Provable secure dynamic lightweight group communication in VANETs

AbstractThe advent of group‐oriented communication applications in Vehicular Ad Hoc Networks (VANETs) has trigger research on lightweight privacy‐preserving Secure Group Communication (SGC) in VANETs. In view of this, many researchers proposed privacy‐preserving, authentication, and key agreements schemes. However, these schemes need to address the dynamic nature, heavier processing loads, massive storage, and higher communication. In this direction, we proposed a framework for lightweight dynamic SGC with privacy‐preserving and authentication in VANETs, encompassing (i) A lightweight Elliptic Curve Cryptography (ECC)‐based two‐party key agreement and its extension to a Dynamic Group Key Agreement, in which fixed Road Side Unit (RSU) acts as Group Controller (GC) with superior computational ability than the On‐Board Unit equipped on the vehicles. (ii) An identify‐based authentication and privacy‐preserving schemes using only two lightweight operations XOR and hashing. (iii) A lightweight encryption and decryption with Exclusive Or (XOR) and hashing only. And (iv) a formal security model for SGC in VANETs. The security analysis shows that the proposed system provides confidentiality of session key, anonymity, secure session key enhancement, and immune to password guessing attack, replay attack, insider attack based on an assumption of the computational G‐ECDDH problem. The experimentation is done for authentication, group key agreement, encryption, and decryption times by a varying number of vehicles in the group to 10, 20, 40, 60, 80, and 100 and shown that the proposed technique is taking considerably less computation than other techniques. So the proposed technique is highly desirable in VANETs.

A Novel Trust Model for Secure Group Communication in Distributed Computing

Distributed networks are networks in which each node can act as a server or client and hence any node can provide service to any other node. In such a scenario, establishing a trust model between the service providing user and the service utilizing user is a challenging task. At present, only a few approaches are available in the past literature to provide this facility. Moreover, the existing approaches do not provide high trust accuracy. Therefore,a novel efficient trust model has been proposed in this article to support the secure dynamic group communication in distributed networks. The main advantage of the proposed work is that it provides higher trust accuracy. Moreover, the proposed work takes less memory for maintaining the trust values and increases the packet delivery ratio in comparison with other existing works which are in the literature.

Speech Discrimination in Real-World Group Communication Using Audio-Motion Multimodal Sensing.

Speech discrimination that determines whether a participant is speaking at a given moment is essential in investigating human verbal communication. Specifically, in dynamic real-world situations where multiple people participate in, and form, groups in the same space, simultaneous speakers render speech discrimination that is solely based on audio sensing difficult. In this study, we focused on physical activity during speech, and hypothesized that combining audio and physical motion data acquired by wearable sensors can improve speech discrimination. Thus, utterance and physical activity data of students in a university participatory class were recorded, using smartphones worn around their neck. First, we tested the temporal relationship between manually identified utterances and physical motions and confirmed that physical activities in wide-frequency ranges co-occurred with utterances. Second, we trained and tested classifiers for each participant and found a higher performance with the audio-motion classifier (average accuracy 92.2%) than both the audio-only (80.4%) and motion-only (87.8%) classifiers. Finally, we tested inter-individual classification and obtained a higher performance with the audio-motion combined classifier (83.2%) than the audio-only (67.7%) and motion-only (71.9%) classifiers. These results show that audio-motion multimodal sensing using widely available smartphones can provide effective utterance discrimination in dynamic group communications.

Variable Me mber Group Authentication Protocol using Bivariate Polynomials

Group authentication is required for secure group communication, which ensures that users in the group are valid. When a group user count is not fixed, group authentication has to handle the entry of new users and exit of current users from the group, if necessary. The challenges to group communication are Security, Integrity and Confidentiality. Currently, available group authentication schemes are complex that require heavy computation and communication overheads. Whenever the group membership is changed, the rekeying of group key process is a challenging task. Thus, in this paper, we propose a variable number group authentication mechanism based on the Lagrange interpolation using bi-variate polynomials. Our proposed scheme handles the generation of the group key and validation effectively. The proposed model shares secret keys to the group user and authenticates all users participated in the group using a single computation and individual users when required. The proposed scheme has a group manager (GM) authenticating all group users and also generates a group key for validating member authenticity. GM is responsible for authenticating and validating each user in the group. GM takes care of members entry and exit from the group. During the changes to the group membership, rekeying is necessary. Our proposed scheme efficiently handles the rekeying process. The proposed scheme also handles backward and forward confidentiality during the group conversation. The security analysis of our scheme guarantees Forward Secrecy, Backward Secrecy, Integrity, Confidentiality and Availability. Our proposed method works effectively for dynamic group communications, where the group membership changes quite frequently.

Sender dynamic, non-repudiable, privacy-preserving and strong secure group communication protocol

Establishing a secure communication channel among a group of individuals is a critical issue in group oriented applications. In implementation, besides the basic confidentiality requirement, we also expect the group communications to be sender dynamic, forward secure, non-repudiable and privacy preserving. Traditional approaches, i.e., group key agreement and broadcast encryption cannot achieve the above requirements simultaneously and efficiently. In this paper, we propose our solution to secure group communications using a new security tool called identity based asymmetric group key agreement protocol with sender non-reputation and privacy. The new notion allows a group of users to negotiate a common group encryption key and their respective group decryption keys. After that, users inside/outside the group who have the knowledge of the group encryption key are able to send non-repudiable and privacy-preserving messages to the group confidentially. Further, even all the users’ private keys are later corrupted, the messages broadcasted previously remain secure. Following this definition, we propose a concrete protocol which is proven to be secure against chosen-ciphertext attacks (CCA) directly. We also show the potential applications of our new protocol in instant messaging applications, such as Whatsapp, Wechat, Messenger.

Host mobility key management in dynamic secure group communication

The key management has a fundamental role in securing group communications taking place over vast and unprotected networks. It is concerned with the distribution and update of the keying materials whenever any changes occur in the group membership. Wireless mobile environments enable members to move freely within the networks, which causes more difficulty to design efficient and scalable key management protocols. This is partly because both member location dynamic and group membership dynamic must be managed concurrently, which may lead to significant rekeying overhead. This paper presents a hierarchical group key management scheme taking the mobility of members into consideration intended for wireless mobile environments. The proposed scheme supports the mobility of members across wireless mobile environments while remaining in the group session with minimum rekeying transmission overhead. Furthermore, the proposed scheme alleviates 1-affect-n phenomenon, single point of failure, and signaling load caused by moving members at the core network. Simulation results shows that the scheme surpasses other existing efforts in terms of communication overhead and affected members. The security requirements studies also show the backward and forward secrecy is preserved in the proposed scheme even though the members move between areas.

An efficient group key agreement protocol for secure P2P communication

AbstractThe efficient design of a distributed group key management for a peer to peer (P2P) network with minimal computation complexity in dynamic secure group communication is a challenging issue. This is because of the absence of a centralized coordinator. In order to provide this facility, a self‐composed distributed group key management framework is proposed for secure P2P communication. In this proposed work, group key computation is performed using Chinese remainder theorem and secure communication is performed through RSA encryption algorithm. This self‐composed key management is a one round protocol in which a shared group key is generated using the public key of each individual user, and it is derived from the respective private key. The main advantage of the group key management scheme proposed in this paper is that it reduces the computation complexity of the peer users to O(1). This reduction in computation complexity is achieved by performing one addition and multiplication operation during a single member join and one subtraction operation during a single member leave operation. The proposed algorithm has been implemented and analyzed with well‐known existing distributed group key management protocols and observed that it reduces the computation complexity significantly. Copyright © 2016 John Wiley & Sons, Ltd.

Dynamic group communication for large-scale parallel data mining

Exascale systems are the next frontier in high-performance computing and are expected to deliver a performance of the order of 1018 operations per second using massive multicore processors. Very large- and extreme-scale parallel systems pose critical algorithmic challenges, especially related to concurrency, locality and the need to avoid global communication patterns. This work investigates a novel protocol for dynamic group communication that can be used to remove the global communication requirement and to reduce the communication cost in parallel formulations of iterative data mining algorithms. The protocol is used to provide a communication-efficient parallel formulation of the k-means algorithm for cluster analysis. The approach is based on a collective communication operation for dynamic groups of processes and exploits non-uniform data distributions. Non-uniform data distributions can be either found in real-world distributed applications or induced by means of multidimensional binary search trees. The analysis of the proposed dynamic group communication protocol has shown that it does not introduce significant communication overhead. The parallel clustering algorithm has also been extended to accommodate an approximation error, which allows a further reduction of the communication costs. The effectiveness of the exact and approximate methods has been tested in a parallel computing system with 64 processors and in simulations with 1024 processing elements.

RRG: redundancy reduced gossip protocol for real-time N-to-N dynamic group communication

Real-time group communication is an indispensable part of many interactive multimedia applications over the internet. In scenarios that involve large group sizes, sporadic sources, high user churns, and random network failures, gossip-based protocols can potentially provide advantages over structure-based group communication algorithms in ease of deployment, scalability, and resiliency against churns and failures. In this paper, we propose a novel protocol called Redundancy Reduced Gossip for real-time N-to-N group communication. We show that our proposed protocol can achieve a considerably lower traffic load than conventional push-based gossip protocols and conventional push-pull gossip protocols for the same probability of successful delivery, with higher performance gains in networks with smaller delays. We derive a mathematical model for estimating the frame non-delivery probability and the traffic load from overhead, and demonstrate the general correctness of the model by simulation. We implement a functioning prototype conferencing system using the proposed protocol, completed with functions including NTP synchronization, dynamic group size estimation, redundancy suppression, and other features needed for proper operation. We perform experiments over the campus network and PlanetLab, and the prototype system demonstrates the ability of our protocol to maintain robust performance in real-world network environments.

Multi-Session Key Management Scheme for Multimedia Group Communications

The Internet 2 deployment introduces new capabilities, such as multi-party collaboration, high-scale multimedia assembly and multicast communication. For this reason, the research concerning security is facing new challenges. One such challenge is to create secure multi-session frameworks to ensure the confidentiality of exchanged information. In a multi-session environment, several users are joined at two or more work sessions simultaneously. The confidentiality in these environments can be achieved using cryptographic methods. Unfortunately, the key management, necessary for such environments, creates two main problems: a high complexity in key distribution and a high storage cost. In this paper, we propose an efficient multi-session key management mechanism for dynamic multimedia group communication. Our solution proposes a functional architecture that exploits the overlapping of the user sessions to reduce the redundancy in key distribution. The proposed key management makes use of two key generation strategies: a key derivation technique to reduce the rekey overhead and a pseudorandom number generator that allows the users to generate an independent key per cipher packet.

Key-update distribution in secure group communication

We focus on the problem of distributing key updates in secure dynamic group communication. In secure groups, to reflect changing group membership, the group controller needs to change and distribute new keys to ensure confidentiality of the group communication. However, in the current key management algorithms, which include the well-known logical key hierarchical algorithms, the group controller broadcasts all key updates even if only a subset of users need them. In this paper, we describe key-update distribution algorithms for distributing keys to only those users who need them. Our algorithms consist of a descendant tracking scheme – to track downstream users in the multicast tree and forwarding mechanisms – to forward key updates using the descendant tracking information. The forwarding mechanisms, in turn, depend on the type of key management algorithm used by the group controller. Using our descendant tracking scheme, a node forwards an encrypted key update only if it believes that there are descendents who know the encrypting key which enables them to decrypt the required key update. Our descendant tracking scheme requires minimal state overhead, of the order of log N bits for a group of N users, to be stored at the intermediate nodes in the multicast tree. We also describe an identifier assignment algorithm that assigns closely clustered logical identifiers to users who are in physical proximity in the multicast tree. Our identifier assignment algorithms leverages the fact that logically clustered users require the approximately same set of key updates. We show that our identifier assignment algorithm improves the performance of our key update distribution algorithms as well as that of a previous solution. Furthermore, we show that, our proposed algorithms reduce the cost of secure data distribution in applications where data needs to be sent securely to only a subset of the group users. To validate our algorithms, we tested them on different key management algorithms for distributing key updates and data. Our simulations results show that a bandwidth reduction of up to 55%, compared to broadcast, is achieved by our algorithms. We also discuss implications of topology matching and logical key tree balancing on our key distribution algorithm and show that it is possible to achieve bandwidth saving up to 90% by combining all three techniques.

Modeling and analysis of intrusion detection integrated with batch rekeying for dynamic group communication systems in mobile ad hoc networks

We investigate performance characteristics of secure group communication systems (GCSs) in mobile ad hoc networks that employ intrusion detection techniques for dealing with insider attacks tightly...

Efficient Solution to Password-based Key Exchange for Large Groups

This paper presents an efficient solution to key exchange problem for large groups in the password- based scenario. Our scheme can combine existing group protocols to get a hybrid group key exchange protocol which is efficient in terms of both computation and communication. And the resulting protocol allows users to securely join and leave the group at any time—the so-called dynamic case. For dynamic group communications, we propose an efficient key-updating algorithms so that the group key is only known to the members of the newly formed pool. Furthermore, our proposal does not introduce new idealizing assumptions or high entropy secrets for authentication.

Adaptive clustering for scalable key management in dynamic group communications

Group key management has received a particular attention, these last years, in both academic and industry research communities. This is due to the economical relevance of group-based applications, such as video on demand, video-conferencing, collaborative work, and so forth. The dynamic aspect of group applications due to free membership joins and leaves in addition to members' mobility, makes security further challenging in the context of group communications. In this paper, we propose a novel key management approach based on adaptive clustering of encryption areas in order to tackle both scalability and dynamism issues in secure group communications. We demonstrate the pertinence of our solution through a proof of optimality with respect to the stated optimisation problem, and simulation results that illustrate when and how our solution outperforms other approaches proposed in the literature.

Multiple Key Sharing and Distribution Scheme With$(n,t)$Threshold for NEMO Group Communications

In this paper, a novel secure key sharing and distribution scheme for network mobility (NEMO) group communications is proposed. The scheme offers the capability of multiple key sharing and distribution for current and future application scenarios, and a threshold mechanism that effectively improves flexibility and robustness of the key sharing and distribution process. Both forward and backward secrecy are guaranteed by compulsive key refreshment and automatic key refreshment mechanisms, which provide dynamic in-progress group communication joining/leaving and periodic keys renewal, respectively. Security and performance analysis are presented to demonstrate that the proposed scheme meets the special security requirements for NEMO group communications and is competent for key sharing and distribution service.

A proposal and its evaluations of a re-keying system for dynamic secure group communications

When distributing data by using IP multicast communications, means of ensuring security such as concealing distributed information and authenticating the data sender have become extremely important matters. To resolve these kinds of problems, the authors introduce dynamic secure group communications for enabling access to a multicast communications group by using an encryption key. To realize dynamic secure group communications, the group key must be updated and redistributed (re-keying) when a new user joins a communications group or a group member leaves. When the key is distributed or updated on the network, traffic problems and problems that affect data communications that accompany them must be taken into consideration. To implement services for providing multicast applications on a network, the authors propose a key distribution and updating protocol that takes into consideration system safety and reliability. In particular, they observe the wide-area network topology, determine a subgroup management server that has proxy functions on a LAN segment, and propose a system for collecting together key distribution response messages on that LAN segment and returning them to the key management server. In addition, they assume a general multicast network model and evaluate the proposed technique according to numerical calculations. The evaluation results show that in addition to shortening the key updating time in a large-scale system and reducing its effect on data communications, the proposed technique can reduce the concentration of communication traffic on the group management center. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(2): 11–24, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20389

A proposal and its evaluations of a re-keying system for dynamic secure group communications

When distributing data by using IP multicast communications, means of ensuring security such as concealing distributed information and authenticating the data sender have become extremely important matters. To resolve these kinds of problems, the authors introduce dynamic secure group communications for enabling access to a multicast communications group by using an encryption key. To realize dynamic secure group communications, the group key must be updated and redistributed (re-keying) when a new user joins a communications group or a group member leaves. When the key is distributed or updated on the network, traffic problems and problems that affect data communications that accompany them must be taken into consideration. To implement services for providing multicast applications on a network, the authors propose a key distribution and updating protocol that takes into consideration system safety and reliability. In particular, they observe the wide-area network topology, determine a subgroup management server that has proxy functions on a LAN segment, and propose a system for collecting together key distribution response messages on that LAN segment and returning them to the key management server. In addition, they assume a general multicast network model and evaluate the proposed technique according to numerical calculations. The evaluation results show that in addition to shortening the key updating time in a large-scale system and reducing its effect on data communications, the proposed technique can reduce the concentration of communication traffic on the group management center. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(2): 11–24, 2006; Published online in Wiley InterScience (). DOI 10.1002sscj.20389

Dynamic group communication

Group communication is the basic infrastructure for implementing fault-tolerant replicated servers. While group communication is well understood in the context of static groups (in which the membership does not change), current specifications of dynamic group communication (in which processes can join and leave groups during the computation) have not yet reached the same level of maturity.The paper proposes new specifications – in the primary partition model – for dynamic reliable broadcast (simply called “reliable multicast”), dynamic atomic broadcast (simply called “atomic multicast”) and group membership. In the special case of a static system, the new specifications are identical to the well known static specifications. Interestingly, not only are these new specifications “syntactically” close to the static specifications, but they are also “semantically” close to the dynamic specifications proposed in the literature. We believe that this should contribute to clarify a topic that has always been difficult to understand by outsiders.Finally, the paper shows how to solve atomic multicast, group membership and reliable broadcast. The solution of atomic multicast is close to the (static) atomic broadcast solution based on reduction to consensus. Group membership is solved using atomic multicast. Reliable multicast can be efficiently solved by relying on a thrifty generic multicast algorithm.

Identity-Based Key Agreement for Peer Group Communication from Pairings

Some cryptographic schemes based on the bilinear pairings were proposed recently. In this paper, we apply the pairings on elliptic curve and Elliptic Curve Cryptography to the key agreement of dynamic peer group. Each member performs authentication and contributes a secret data to negotiate a group common key by means of a binary key tree. The proposed protocol does not need a dedicated central server to perform the key agreement, and the overhead is distributed among the group members. To provide a secure dynamic group communication, the key renewing mechanism has to be included. While the member joins/leaves, the group session key will be renewed to provide the backward/forward privacy, respectively. The key renewing is much efficient because it is only confined to the keys of the key-path. The proposed protocol is flexible while the change of membership is frequent.

Dynamic multicast routing in VLSI

As real-time applications requiring dynamic group communication emerges, existing multicast routing algorithms must be improved to cater for high-speed routing decisions. Most of the reported efficient multicast routing algorithms for real-time applications construct a multicast tree using the Dijkstra's algorithm. However, they require reconstruction of the tree when there are group membership changes or faulty links/nodes in the session. In this paper, a dynamic routing strategy that does not rely on the construction of the multicast tree is presented. It is based on the “clustering technique” and it lends well for VLSI implementation. The Cluster Unit was implemented using VHDL and a suitable architecture for the routing strategy has been proposed. Performance evaluations based on software simulations show that the proposed routing strategy performs better than the most widely used multicast routing algorithm when the number of nodes become large. Moreover, performance comparisons based on the VHDL implementation of the Cluster Unit show that the proposed technique performs significantly better when realised in VLSI.