This paper presents an efficient algorithm for the secure group key management of mobile users. The most promising protocols to deal with group key management are those based on logical key hierarchy (LKH). The LKH model reduces to logarithmic size the resources needed: computation time, message exchanged, and memory space. In the framework of the LKH model, we present a new protocol LKH++ that outperforms the other proposed solutions in the literature. Such performance improvements are obtained exploiting both the properties of one-way hash functions and the information that the users already share in the LKH model. In particular, when a user eviction occurs in LKH++, each remaining user autonomously constructs a new key along the path from the evicted user to the root as a function of a specific logical child key. Therefore, the center can carry on the re-keying phase by distributing only a subset of the new keys and by reducing the number of communications to the users. When a join occurs, a minimal information is broadcast, while most of the communications are unicast toward just the joining user. The proposed LKH++ protocol establishes a group communication of n users requiring to unicast ((n-1)logn)/2 keys, while standard algorithms require to deliver nlogn keys. Such a solution allows the users to form promptly a new group if the wireless ad hoc network should be reconfigured. Moreover, the proposed extension to deal with mass leave and mass join allows a considerable savings in the messages sent by the center, as well as in the computations required by both the center and the users. Finally, the LKH++ protocol enhances the reliability of the key management due to the reduced number of communications needed in the re-keying phase.
{"title":"Efficient and secure keys management for wireless mobile communications","authors":"R. D. Pietro, L. Mancini, S. Jajodia","doi":"10.1145/584490.584504","DOIUrl":"https://doi.org/10.1145/584490.584504","url":null,"abstract":"This paper presents an efficient algorithm for the secure group key management of mobile users. The most promising protocols to deal with group key management are those based on logical key hierarchy (LKH). The LKH model reduces to logarithmic size the resources needed: computation time, message exchanged, and memory space. In the framework of the LKH model, we present a new protocol LKH++ that outperforms the other proposed solutions in the literature. Such performance improvements are obtained exploiting both the properties of one-way hash functions and the information that the users already share in the LKH model. In particular, when a user eviction occurs in LKH++, each remaining user autonomously constructs a new key along the path from the evicted user to the root as a function of a specific logical child key. Therefore, the center can carry on the re-keying phase by distributing only a subset of the new keys and by reducing the number of communications to the users. When a join occurs, a minimal information is broadcast, while most of the communications are unicast toward just the joining user. The proposed LKH++ protocol establishes a group communication of n users requiring to unicast ((n-1)logn)/2 keys, while standard algorithms require to deliver nlogn keys. Such a solution allows the users to form promptly a new group if the wireless ad hoc network should be reconfigured. Moreover, the proposed extension to deal with mass leave and mass join allows a considerable savings in the messages sent by the center, as well as in the computations required by both the center and the users. Finally, the LKH++ protocol enhances the reliability of the key management due to the reduced number of communications needed in the re-keying phase.","PeriodicalId":344182,"journal":{"name":"Principles of Mobile Computing","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127671989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Anceaume, A. Datta, M. Potop-Butucaru, G. Simon
The information dissemination in mobile networks is an important but complex and challenging problem. Designing suitable communication primitives for these systems is critical. One of these primitives is the publish/subscribe paradigm. The publish/subscribe is a strategy to establish communication between the information providers (publishers) and information consumers (subscribers) in a distributed system. Our work focuses on an appropriate distributed infrastructure suitable for a scalable implementation of a publish/subscribe system. We present a formal model which is adapted for the peer-based particular subscription criteria of publish/subscribe systems. Moreover, we propose a general deterministic information diffusion scheme for mobile systems. The three main features of our communication scheme are the following: First, our scheme is well-adapted to scalable systems without compromising any subscription criteria or network reorganization. Second, we maintain the anonymity of the distributed system --- in order to maintain the network structure, we need only local information. Third, our solution is fully decentralized and modular, thus making it appropriate for practical implementations.
{"title":"Publish/subscribe scheme for mobile networks","authors":"E. Anceaume, A. Datta, M. Potop-Butucaru, G. Simon","doi":"10.1145/584490.584505","DOIUrl":"https://doi.org/10.1145/584490.584505","url":null,"abstract":"The information dissemination in mobile networks is an important but complex and challenging problem. Designing suitable communication primitives for these systems is critical. One of these primitives is the publish/subscribe paradigm. The publish/subscribe is a strategy to establish communication between the information providers (publishers) and information consumers (subscribers) in a distributed system. Our work focuses on an appropriate distributed infrastructure suitable for a scalable implementation of a publish/subscribe system. We present a formal model which is adapted for the peer-based particular subscription criteria of publish/subscribe systems. Moreover, we propose a general deterministic information diffusion scheme for mobile systems. The three main features of our communication scheme are the following: First, our scheme is well-adapted to scalable systems without compromising any subscription criteria or network reorganization. Second, we maintain the anonymity of the distributed system --- in order to maintain the network structure, we need only local information. Third, our solution is fully decentralized and modular, thus making it appropriate for practical implementations.","PeriodicalId":344182,"journal":{"name":"Principles of Mobile Computing","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129195906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper proposes a distributed algorithm by which a collection of mobile robots roaming on a plane move to form a circle. The algorithm operates under the premises that robots (1) are unable to recall past actions and observations (i.e., oblivious), (2) cannot be distinguished from each others (i.e., anonymous), (3) share no common sense of direction, and (4) are unable to communicate in any other ways than by observing each others position.
{"title":"Circle formation for oblivious anonymous mobile robots with no common sense of orientation","authors":"X. Défago, A. Konagaya","doi":"10.1145/584490.584509","DOIUrl":"https://doi.org/10.1145/584490.584509","url":null,"abstract":"This paper proposes a distributed algorithm by which a collection of mobile robots roaming on a plane move to form a circle. The algorithm operates under the premises that robots (1) are unable to recall past actions and observations (i.e., oblivious), (2) cannot be distinguished from each others (i.e., anonymous), (3) share no common sense of direction, and (4) are unable to communicate in any other ways than by observing each others position.","PeriodicalId":344182,"journal":{"name":"Principles of Mobile Computing","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129251276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Most previous work on medium access control (MAC) protocols for wireless ad hoc networks has focused on the twin goals of maximising throughput and minimising average packet delay as required for general-purpose applications.In this paper we describe a new MAC protocol for use in multi-hop ad hoc networks whose goal is to provide, with high probability, time-bounded access to the wireless medium for applications with guaranteed response time requirements.The Time-Bounded Medium Access Control (TBMAC) protocol is based on time-division multiple access with dynamic but predictable slot allocation. TBMAC uses a light-weight atomic multicast protocol to achieve distributed agreement on slot allocation and employs location information to minimise contention for slots.TBMAC is the first time-bounded MAC protocol for multi-hop wireless ad hoc networks. In this paper we describe the protocol and provide a number of time bounds for the transmission of messages.
以前关于无线自组织网络的介质访问控制(MAC)协议的大多数工作都集中在通用应用程序所需的最大吞吐量和最小平均数据包延迟的双重目标上。在本文中,我们描述了一种用于多跳自组织网络的新MAC协议,其目标是为具有保证响应时间要求的应用程序提供高概率的有时间限制的无线介质访问。TBMAC (Time-Bounded Medium Access Control)协议是一种基于分时多址的协议,具有动态但可预测的时隙分配。TBMAC采用轻量级原子多播协议实现槽位分配的分布式协议,并利用位置信息最小化槽位争用。TBMAC是第一个针对多跳无线自组织网络的有时间限制的MAC协议。在本文中,我们描述了该协议,并为消息的传输提供了一些时间限制。
{"title":"Time bounded medium access control for ad hoc networks","authors":"R. Cunningham, V. Cahill","doi":"10.1145/584490.584492","DOIUrl":"https://doi.org/10.1145/584490.584492","url":null,"abstract":"Most previous work on medium access control (MAC) protocols for wireless ad hoc networks has focused on the twin goals of maximising throughput and minimising average packet delay as required for general-purpose applications.In this paper we describe a new MAC protocol for use in multi-hop ad hoc networks whose goal is to provide, with high probability, time-bounded access to the wireless medium for applications with guaranteed response time requirements.The Time-Bounded Medium Access Control (TBMAC) protocol is based on time-division multiple access with dynamic but predictable slot allocation. TBMAC uses a light-weight atomic multicast protocol to achieve distributed agreement on slot allocation and employs location information to minimise contention for slots.TBMAC is the first time-bounded MAC protocol for multi-hop wireless ad hoc networks. In this paper we describe the protocol and provide a number of time bounds for the transmission of messages.","PeriodicalId":344182,"journal":{"name":"Principles of Mobile Computing","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125056416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ad hoc networks consist of wireless hosts that communicate with each other in the absence of a fixed infrastructure. Clustering is commonly used in order to limit the amount of routing information stored and maintained at individual hosts. A k-clustering is a framework in which the wireless network is divided into non-overlapping sub networks, also referred to as clusters, and where every two wireless hosts in a sub network are at most k hops from each other. The algorithmic complexity of k-clustering is known to be NP-Complete for simple undirected graphs. For the special family of graphs that represent ad hoc wireless networks, modeled as unit disk graphs, we introduce a two phase distributed polynomial time and message complexity approximation solution with O(k) worst case ratio over the optimal solution. The first phase constructs a spanning tree of the network and the second phase then partitions the spanning tree into subtrees with bounded diameters.
{"title":"K-clustering in wireless ad hoc networks","authors":"Yaacov Fernandess, D. Malkhi","doi":"10.1145/584490.584497","DOIUrl":"https://doi.org/10.1145/584490.584497","url":null,"abstract":"Ad hoc networks consist of wireless hosts that communicate with each other in the absence of a fixed infrastructure. Clustering is commonly used in order to limit the amount of routing information stored and maintained at individual hosts. A k-clustering is a framework in which the wireless network is divided into non-overlapping sub networks, also referred to as clusters, and where every two wireless hosts in a sub network are at most k hops from each other. The algorithmic complexity of k-clustering is known to be NP-Complete for simple undirected graphs. For the special family of graphs that represent ad hoc wireless networks, modeled as unit disk graphs, we introduce a two phase distributed polynomial time and message complexity approximation solution with O(k) worst case ratio over the optimal solution. The first phase constructs a spanning tree of the network and the second phase then partitions the spanning tree into subtrees with bounded diameters.","PeriodicalId":344182,"journal":{"name":"Principles of Mobile Computing","volume":"280 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116589080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ad-hoc networks facilitate interconnectivity between mobile devices without the support of a network infrastructure. In this paper we propose a flexible credential verification mechanism, which improves the likelihood that participants in an ad-hoc network can verify each other's credentials despite the lack of access to certification and attribute authorities. Users maintain Credential Assertion Statements (CASs), which are formed through extraction of X.509 and attribute certificates into an interoperable XML form. Trusted entities that can verify the credentials listed in the CAS can then issue signed Assertion Signature Statements (ASSs) to other participants in the ad-hoc network. In addition, each user maintains a key ring, which comprises the list of public-keys trusted to sign credential assertion statements. All public-keys in the ring are assigned a trustworthiness level. When a user presents his/her CAS together with matching ASSs to a verifier, the verifier checks the signatures in the ASSs against its key ring to determine whether credentials in the CAS are authentic and acceptable. Transitivity of trust is generally not allowed, but there are exceptional cases in which it is permitted.
{"title":"Towards flexible credential verification in mobile ad-hoc networks","authors":"S. Keoh, Emil C. Lupu","doi":"10.1145/584490.584503","DOIUrl":"https://doi.org/10.1145/584490.584503","url":null,"abstract":"Ad-hoc networks facilitate interconnectivity between mobile devices without the support of a network infrastructure. In this paper we propose a flexible credential verification mechanism, which improves the likelihood that participants in an ad-hoc network can verify each other's credentials despite the lack of access to certification and attribute authorities. Users maintain Credential Assertion Statements (CASs), which are formed through extraction of X.509 and attribute certificates into an interoperable XML form. Trusted entities that can verify the credentials listed in the CAS can then issue signed Assertion Signature Statements (ASSs) to other participants in the ad-hoc network. In addition, each user maintains a key ring, which comprises the list of public-keys trusted to sign credential assertion statements. All public-keys in the ring are assigned a trustworthiness level. When a user presents his/her CAS together with matching ASSs to a verifier, the verifier checks the signatures in the ASSs against its key ring to determine whether credentials in the CAS are authentic and acceptable. Transitivity of trust is generally not allowed, but there are exceptional cases in which it is permitted.","PeriodicalId":344182,"journal":{"name":"Principles of Mobile Computing","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132449537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper describes some preliminary steps towards defining a consistency criteria for mobile replicated systems using operational transformations. Our criterion lies between traditional strong criteria, preventing divergence, and traditional weak criteria, not enforcing any eventual form of convergence. We give a precise definition of our criterion and discuss its use to state the correctness and incorrectness of some existing practical algorithms.
{"title":"On the consistency problem in mobile distributed computing","authors":"R. Guerraoui, C. Hari","doi":"10.1145/584490.584501","DOIUrl":"https://doi.org/10.1145/584490.584501","url":null,"abstract":"This paper describes some preliminary steps towards defining a consistency criteria for mobile replicated systems using operational transformations. Our criterion lies between traditional strong criteria, preventing divergence, and traditional weak criteria, not enforcing any eventual form of convergence. We give a precise definition of our criterion and discuss its use to state the correctness and incorrectness of some existing practical algorithms.","PeriodicalId":344182,"journal":{"name":"Principles of Mobile Computing","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128201663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Smart Dust is a set of a ast number of ultra-small fully autonomous computing and communication devices, with very restricted energy and computing capabilities, that cooperate to quickly and efficiently accomplish a large sensing task. Smart Dust can be very useful in practice i.e. in the local detection of a remote crucial event and the propagation of data reporting its realization. In this work we make an effort towards the research on smart dust from a basic algorithmic point of view. We first provide a simple but realistic model for smart dust and present an interesting problem, which is how to propagate efficiently information on an event detected locally. Then we present smart dust protocols for local detection and propagation that are simple enough to be implemented on real smart dust systems, and perform, under some simplifying assumptions, a rigorous average case analysis of their efficiency and energy consumption (and their interplay). This analysis leads to concrete results showing that our protocols are very efficient.
{"title":"Smart dust protocols for local detection and propagation","authors":"I. Chatzigiannakis, S. Nikoletseas, P. Spirakis","doi":"10.1145/584490.584493","DOIUrl":"https://doi.org/10.1145/584490.584493","url":null,"abstract":"Smart Dust is a set of a ast number of ultra-small fully autonomous computing and communication devices, with very restricted energy and computing capabilities, that cooperate to quickly and efficiently accomplish a large sensing task. Smart Dust can be very useful in practice i.e. in the local detection of a remote crucial event and the propagation of data reporting its realization. In this work we make an effort towards the research on smart dust from a basic algorithmic point of view. We first provide a simple but realistic model for smart dust and present an interesting problem, which is how to propagate efficiently information on an event detected locally. Then we present smart dust protocols for local detection and propagation that are simple enough to be implemented on real smart dust systems, and perform, under some simplifying assumptions, a rigorous average case analysis of their efficiency and energy consumption (and their interplay). This analysis leads to concrete results showing that our protocols are very efficient.","PeriodicalId":344182,"journal":{"name":"Principles of Mobile Computing","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125033952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An efficient name resolution scheme is the cornerstone of any peer-to-peer network. The name resolution scheme proposed by Plaxton, Rajaraman, and Richa, which we hereafter refer to as the PRR scheme, is a scalable name resolution scheme that also provides provable locality properties. However, since PRR goes to extra lengths to provide these locality properties, it is somewhat complicated. In this paper, we propose a scalable, locality-aware, and fault-tolerant name resolution scheme which can be considered a simplified version of PRR. Although this new scheme does not provide as strong locality guarantees as PRR, it exploits locality heuristically yet effectively.
{"title":"On name resolution in peer-to-peer networks","authors":"Xiaozhou Li, C. Plaxton","doi":"10.1145/584490.584507","DOIUrl":"https://doi.org/10.1145/584490.584507","url":null,"abstract":"An efficient name resolution scheme is the cornerstone of any peer-to-peer network. The name resolution scheme proposed by Plaxton, Rajaraman, and Richa, which we hereafter refer to as the PRR scheme, is a scalable name resolution scheme that also provides provable locality properties. However, since PRR goes to extra lengths to provide these locality properties, it is somewhat complicated. In this paper, we propose a scalable, locality-aware, and fault-tolerant name resolution scheme which can be considered a simplified version of PRR. Although this new scheme does not provide as strong locality guarantees as PRR, it exploits locality heuristically yet effectively.","PeriodicalId":344182,"journal":{"name":"Principles of Mobile Computing","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129329157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The deployment of wireless applications or protocols in the context of Mobile Ad-hoc NETworks (MANETs), often requires to step through a simulation phase. For the results of the simulation to be meaningful, it is important that the model on which is based the simulator matches as closely as possible the reality. In this paper we present the simulation results of a straightforward algorithm using several popular simulators (OPNET Modeler, NS-2, GloMoSim). The results tend to show that significant divergences exist between the simulators. This can be explained partly by the mismatching of the modelisation of each simulator and also by the different levels of detail provided to implement and configure the simulated scenarios.
{"title":"On the accuracy of MANET simulators","authors":"D. Cavin, Y. Sasson, A. Schiper","doi":"10.1145/584490.584499","DOIUrl":"https://doi.org/10.1145/584490.584499","url":null,"abstract":"The deployment of wireless applications or protocols in the context of Mobile Ad-hoc NETworks (MANETs), often requires to step through a simulation phase. For the results of the simulation to be meaningful, it is important that the model on which is based the simulator matches as closely as possible the reality. In this paper we present the simulation results of a straightforward algorithm using several popular simulators (OPNET Modeler, NS-2, GloMoSim). The results tend to show that significant divergences exist between the simulators. This can be explained partly by the mismatching of the modelisation of each simulator and also by the different levels of detail provided to implement and configure the simulated scenarios.","PeriodicalId":344182,"journal":{"name":"Principles of Mobile Computing","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126789345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}