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NOA-AID (Network Overlays for Adaptive information Aggregation, Indexing and Discovery on the fog) is an approach for decentralized indexing, aggregation and discovery of data belonging to streams. It is organized on two network layers. The upper layer is in charge of delivering an information discovery approach by providing a distributed index structure. The lower layer is devoted to resource aggregation based on epidemic protocols designed for highly dynamic environment, well suited to stream-oriented scenarios. It defines a flexible approach to express queries targeting highly heterogeneous data, as well as a self-organizing dynamic system allowing the optimal resolution of queries on the most suitable stream producers. The paper also presents a theoretical study and discusses the costs related to information management operations; it also gives an empirical validation of findings. Finally, it reports an extended experimental evaluation that demonstrated the ability of NOA-AID to be effective and efficient for retrieving information extracted from streams in highly-dynamic and distributed processing architectures. [ABSTRACT FROM AUTHOR]

Many safety-critical real-time applications are implemented using distributed architectures, composed of heterogeneous processing elements interconnected in a network. Our focus in this paper is on the TTEthernet protocol, a deterministic, synchronized and congestion-free network protocol based on the Ethernet standard and compliant with the ARINC 664 Specification Part 7. TTEthernet is highly suitable for safety-critical real-time applications since it offers separation for messages using the concept of virtual links and supports three time-criticality classes: Time-Triggered (TT), Rate-Constrained (RC) and Best-Effort. In this paper we are interested in the design optimization of TTEthernet networks used to transmit real-time application messages. Given the set of TT and RC messages, and the topology of the network, our approach optimizes the packing of messages in frames, the assignment of frames to virtual links, the routing of virtual links and the TT static schedules, such that all frames are schedulable and the worst-case end-to-end delay of the RC messages is minimized. We propose a Tabu Search-based metaheuristic for this optimization problem. The proposed algorithm has been evaluated using several benchmarks. [ABSTRACT FROM AUTHOR]

In table routing protocols such as link state routing, every node in the network periodically broadcasts its link state and the state of its neighbors. These routing updates result in the transmission of a large number of packets. Some of these packets contain correlated or even redundant data which could be compressed if there is central management in the network. However, in autonomous networks, each node acts as a router, in which case central coordination is not possible. In this paper, compressed sensing is used to reduce routing traffic overhead. This can be done at nodes which have greater processing capabilities and no power consumption limitations such as backbone nodes in wireless mesh networks. A method is proposed to select a subset of nodes and thus a subset of links to probe their state. The sensed states are encoded to generate a low dimension sampled vector. This compressed link state vector is broadcast to the entire network. Nodes can then reconstruct link states from this vector using side information. Performance results are presented which demonstrate accurate anomaly detection while adapting to topology changes. Further, it is shown that a proper choice of weighting coefficients in the sampling process can improve detection performance. [ABSTRACT FROM AUTHOR]

Routing protocols in wireless mesh networks considering its special topology has been an open field for years. Routing methods which are used now could be classified to two groups. Some methods based on common wireless routing protocols with some changes in metrics and other methods based on opportunistic routing methods. In this paper we use the compressed sensing idea to suggest a new topology update protocol for backbone nodes in WMNs. Stable nodes with low probability of failure beside its capability of processing could support a compressed sensing problem for detection of failed links in predefined topology. In our proposed routing method, link states of backbone nodes should be randomly sampled. Then this sampled link states would be coded. All backbone nodes of WMN would be advertised about these codes by some a few nodes which broadcast these codes. So we would have a compressed sense of link states in all nodes. Our proposed verification based reconstruction method could be used in nodes to detection of failed links. Simulation results show that about 60% overhead decrease of routing protocol would be reached by this method with up to 95% probability of correct detection of failed links. [ABSTRACT FROM AUTHOR]

Sleep scheduling, which is putting some sensor nodes into sleep mode without harming network functionality, is a common method to reduce energy consumption in dense wireless sensor networks. This paper proposes a distributed and energy efficient sleep scheduling and routing scheme that can be used to extend the lifetime of a sensor network while maintaining a user defined coverage and connectivity. The scheme can activate and deactivate the three basic units of a sensor node (sensing, processing, and communication units) independently. The paper also provides a probabilistic method to estimate how much the sensing area of a node is covered by other active nodes in its neighborhood. The method is utilized by the proposed scheduling and routing scheme to reduce the control message overhead while deciding the next modes (full-active, semi-active, inactive/sleeping) of sensor nodes. We evaluated our estimation method and scheduling scheme via simulation experiments and compared our scheme also with another scheme. The results validate our probabilistic method for coverage estimation and show that our sleep scheduling and routing scheme can significantly increase the network lifetime while keeping the message complexity low and preserving both connectivity and coverage. [ABSTRACT FROM AUTHOR]

This paper describes the verification of Secure Electronic Transaction (SET), an e-commerce protocol by VISA and MasterCard. The main tasks are to comprehend the written documentation, to produce an accurate formal model, to identify specific protocol goals, and, finally, to prove them. The main obstacles are the protocol’s complexity (due in part to its use of digital envelopes) and its unusual goals involving partial information sharing. Our verification efforts show that the protocol does not completely satisfy its goals, although the flaws are minor. The primary outcome of the project is experience with verification of enormous and complicated protocols. This paper summarizes the project - the details appear elsewhere [11, 12 , 13 ] - focusing on the issues and the conclusions. [ABSTRACT FROM AUTHOR]

Nowadays Wi-Fi is the most mature technology for wireless-Internet access. Despite the large (and ever increasing) diffusion of Wi-Fi hotspots, energy limitations of mobile devices are still an issue. To deal with this, the standard 802.11 includes a Power-Saving Mode (PSM), but not much attention has been devoted by the research community to understand its performance in depth. We think that this paper contributes to fill the gap. We focus on a typical Wi-Fi hotspot scenario, and assess the dependence of the PSM behavior on several key parameters such as the packet loss probability, the Round Trip Time, the number of users within the hotspot. We show that during traffic bursts PSM is able to save up to 90% of the energy spent when no energy management is used, and introduces a limited additional delay. Unfortunately, in the case of long inactivity periods between bursts, PSM is not the optimal solution for energy management. We thus propose a very simple Cross-Layer Energy Manager (XEM) that dynamically tunes its energy-saving strategy depending on the application behavior and key network parameters. XEM does not require any modification to the applications or to the 802.11 standard, and can thus be easily integrated in current Wi-Fi devices. Depending on the network traffic pattern, XEM reduces the energy consumption of an additional 20–96% with respect to the standard PSM. [ABSTRACT FROM AUTHOR]

A central problem for structured peer-to-peer networks is topology maintenance, that is, how to properly update neighbor variables when nodes join or leave the network, possibly concurrently. In this paper, we consider the maintenance of the ring topology, the basisof several peer-to-peer networks, in the fault-free environment. We design, and prove the correctness of, protocols that maintain a bidirectional ring under both joins and leaves. Our protocols update neighbor variables once a membership change occurs. We prove the correctness of our protocols using an assertional proof method, that is, we first identify a global invariant for a protocol and then show that every action of the protocol preserves the invariant. Our protocols are simple and our proofs are rigorous and explicit. [ABSTRACT FROM AUTHOR]

In this paper, we propose INCP, inter-flow network coding protocol, for wireless mesh networks. INCP is designed with the concept of Layered Approach. It acts as a distinct layer above the MAC and has close cooperation with IP layer. INCP exploits the opportunities of network coding through multiple unicast sessions to decrease the number of transmissions, thereby increasing the aggregated throughput. Unlike most prior work that is mainly theoretical, INCP addresses the practical issues of network coding such as impact of lossy links, enabling/disabling RTS/CTS mechanism, packet size and its variation. We consider a retransmission mechanism to ensure a reliable broadcasting. We analyze the cost of this approach by providing a theoretical formulation for the amount of required bandwidth for successful broadcasting a coded packet to n neighbors. Further, we examine the coding gain for lossy networks by considering the ETX metric for routing in addition to traditionally shortest-path metric. The results, implemented in ns-3, show that not only INCP increases network throughput, but also improves the fairness of the IEEE 802.11 MAC. Moreover, the gain for real MAC is greater than the theoretical gain in most cases. The performance gain of INCP reaches up to several folds depending on the traffic model and congestion level. [ABSTRACT FROM AUTHOR]

This paper presents a novel three-party key agreement protocol using password authentication, which enables each client sharing a long-lived secret only with a trusted server to exchange confidential and authenticated information with another client over an insecure network via the server. The proposed protocol is based on extended chaotic maps and adopts the technique that the clients can publicly exchange the factors for generating the session key without the help of the server such that the numbers of transmissions are reduced. A round-efficient version of the proposed key agreement protocol is also described. Compared to related chaotic map-based approaches, the proposed protocol not only possesses higher security and lower computational cost, but also has fewer transmissions. Additionally, the proposed protocol is proven secure in the random oracle model and realizes optimal in communications. [ABSTRACT FROM AUTHOR]

Client puzzles have been advocated as a promising countermeasure to denial-of-service (DoS) attacks in recent years. However, how to operationalize this idea in network protocol stacks still has not been sufficiently studied. In this paper, we describe our research on a multi-layer puzzle-based DoS defense architecture, which embeds puzzle techniques into both end-to-end and IP-layer services. Specifically, our research results in two new puzzle techniques: puzzle auctions for end-to-end protection and congestion puzzles for IP-layer protection. We present the designs of these approaches and evaluations of their efficacy. We demonstrate that our techniques effectively mitigate DoS threats to IP, TCP and application protocols; maintain full interoperability with legacy systems; and support incremental deployment. We also provide a game theoretic analysis that sheds light on the potential to use client puzzles for incentive engineering: the costs of solving puzzles on an attackers’ behalf could motivate computer owners to more aggressively cleanse their computers of malware, in turn hindering the attacker from capturing a large number of computers with which it can launch DoS attacks. [ABSTRACT FROM AUTHOR]

Wireless networking has witnessed an explosion of interest from consumers in recent years for its applications in mobile and personal communications. As wireless networks become an integral component of the modern communication infrastructure, energy efficiency will be an important design consideration due to the limited battery life of mobile terminals. Power conservation techniques are commonly used in the hardware design of such systems. Since the network interface is a significant consumer of power, considerable research has been devoted to low-power design of the entire network protocol stack of wireless networks in an effort to enhance energy efficiency. This paper presents a comprehensive summary of recent work addressing energy efficient and low-power design within all layers of the wireless network protocol stack. [ABSTRACT FROM AUTHOR]

Network protocols in cellular wireless data networks must update routes as a mobile host moves between cells. These routing updates combined with some associated state changes are called handoffs. Most current handoff schemes in wireless networks result in data loss or large variations in packet delivery times. Unfortunately, many applications, such as real-time multimedia applications and reliable transport protocols, adapt to long term estimates of end-to-end delay and loss. Violations and rapid fluctuations of these estimates caused by handoff processing often result in degraded performance. For example, loss during handoff adversely affects TCP performance [4], and high packet loss and variable delays result in poor real-time multimedia performance. In this paper, we describe a multicast-based protocol that eliminates data loss and incurs negligible delays during a handoff. The basic technique of the algorithm is to anticipate a handoff using wireless network information in the form of received signal strengths and to multicast data destined for the mobile host to nearby base stations in advance. This routing, combined with intelligent buffering techniques at the base stations, enables very rapid routing updates and eliminates data loss without the use of explicit data forwarding. We have implemented this protocol using IP Multicast and Mobile IP-like routing. In our implementation, handoffs typically take between 8 and 15 ms to complete and result in no data loss. [ABSTRACT FROM AUTHOR]

Flying Ad-Hoc Networks (FANETs) consist of multi-Unmanned Aerial Vehicle (UAV) nodes with ad-hoc networking capabilities. FANETs are increasingly gaining popularity in real-world applications where communication infrastructure is lacking. In this work, an application of FANET in monitoring the geographical spread of a certain type of disaster event has been showcased. For this task, suitable network topology construction algorithms have been developed. Additionally, various protocols of the network protocol stack have been implemented for this FANET. A bespoke co-simulator platform has been developed to simulate this network. The co-simulator platform makes use of a network simulator (NS-3), and robot simulator (Gazebo) interfaced with each other using an interlinking framework of Robot Operating System (ROS). This platform has been used to simulate network topology construction algorithms as well as networking protocols. The proposed FANET has been analyzed for the deployment of an optimum number of drones in the varying profile of disaster event. Also, the temporal analysis has been conducted to showcase the time-effectiveness of the FANET deployment in such cases. For example, if the disaster event is located at 250 m from the Base Station (BS), with a spread of around 70 m radius, the total number of drones required is 16, and the deployment time is merely 4.25 mins. Along with this, a link analysis of the network also has been conducted for calculating throughput. It indicates that the FANET can be utilized for multimedia streaming as there is ample scope for throughput enhancement. [ABSTRACT FROM AUTHOR]

As healthcare in many countries faces an aging population and rising costs, mobile sensing technologies promise a new opportunity. Using mobile health (mHealth) sensing, which uses medical sensors to collect data about the patients, and mobile phones to act as a gateway between sensors and electronic health record systems, caregivers can continuously monitor the patients and deliver better care. Furthermore, individuals can become better engaged in monitoring and managing their own health. Although some work on mHealth sensing has addressed security, achieving strong privacy for low-power sensors remains a challenge. We make three contributions. First, we propose an mHealth sensing protocol that provides strong security and privacy properties at the link layer, with low energy overhead, suitable for low-power sensors. The protocol uses three novel techniques: adaptive security, to dynamically modify transmission overhead; MAC striping, to make forgery difficult even for small-sized Message Authentication Codes; and asymmetric resource requirements, in recognition of the limited resources in tiny mHealth sensors. Second, we demonstrate its feasibility by implementing a prototype on a Chronos wrist device, and evaluating it experimentally. Third, we provide a security, privacy, and energy analysis of our system. [ABSTRACT FROM AUTHOR]

The domain name system (DNS) provides a translation between readable domain names and IP addresses. The DNS is a key infrastructure component of the Internet and a prime target for a variety of attacks. One of the most significant threats to DNS' well-being is a DNS poisoning attack in which the DNS responses are maliciously replaced, or poisoned, by an attacker. To identify this kind of attack, we start by an analysis of different kinds of response times. We present an analysis of typical and atypical response times, while differentiating between the different levels of DNS servers' response times, from root servers down to internal caching servers. We successfully identify empirical DNS poisoning attacks based on a novel method for DNS response timing analysis. We then present a system we developed to validate our technique that does not require any changes to the DNS protocol or any existing network equipment. Our validation system tested data from different architectures including LAN and cloud environments and real data from an internet service provider. Our method and system differ from most other DNS poisoning detection methods and achieved high detection rates exceeding 98%. These findings suggest that when used in conjunction with other methods, they can considerably enhance the accuracy of these methods. [ABSTRACT FROM AUTHOR]

Secure channel establishment protocols such as Transport Layer Security (TLS) are some of the most important cryptographic protocols, enabling the encryption of Internet traffic. Reducing latency (the number of interactions between parties before encrypted data can be transmitted) in such protocols has become an important design goal to improve user experience. The most important protocols addressing this goal are TLS 1.3, the latest TLS version standardized in 2018 to replace the widely deployed TLS 1.2, and Quick UDP Internet Connections (QUIC), a secure transport protocol from Google that is implemented in the Chrome browser. There have been a number of formal security analyses for TLS 1.3 and QUIC, but their security, when layered with their underlying transport protocols, cannot be easily compared. Our work is the first to thoroughly compare the security and availability properties of these protocols. Toward this goal, we develop novel security models that permit “layered” security analysis. In addition to the standard goals of server authentication and data confidentiality and integrity, we consider the goals of IP spoofing prevention, key exchange packet integrity, secure channel header integrity, and reset authentication, which capture a range of practical threats not usually taken into account by existing security models that focus mainly on the cryptographic cores of the protocols. Equipped with our new models we provide a detailed comparison of three low-latency layered protocols: TLS 1.3 over TCP Fast Open (TFO), QUIC over UDP, and QUIC[TLS] (a new design for QUIC that uses TLS 1.3 key exchange) over UDP. In particular, we show that TFO’s cookie mechanism does provably achieve the security goal of IP spoofing prevention. Additionally, we find several new availability attacks that manipulate the early key exchange packets without being detected by the communicating parties. By including packet-level attacks in our analysis, our results shed light on how the reliability, flow control, and congestion control of the above layered protocols compare, in adversarial settings. We hope that our models will help protocol designers in their future protocol analyses and that our results will help practitioners better understand the advantages and limitations of secure channel establishment protocols. [ABSTRACT FROM AUTHOR]

In distributed computing, location transparency-the decoupling of objects from their physical location-is desirable in that it can simplify application development and enables efficient resource allocation. Many systems for location transparency are built on TCP/IP. We argue that addressing mobile objects in terms of temporary hosts may not be the best design decision. Object migration makes it necessary to use dedicated routing infrastructures, e.g., location servers, to deliver inter-object messages. This incurs high costs in terms of complexity, overhead, and latency. Here, we defer object overlay routing to a networking layer, by replacing TCP/IP with a location-independent routing scheme which directs messages to destinations determined by flat identifiers instead of IP addresses. Consequently, messages are delivered directly to objects, instead of possibly out-of-date locations. We explore the scheme using a small object-based language with asynchronous message passing, similar to Core Erlang. We provide a standard, network-oblivious operational semantics of this language, and a network-aware semantics which accounts for many aspects of distribution and routing. The main result is that program execution on top of an abstract network of processing nodes connected by asynchronous point-to-point communication channels preserves network-oblivious behavior in a sound and fully abstract way, in the sense of contextual equivalence. This is a novel and strong result for such a low-level model. Previous work has addressed distributed implementations only for fully connected TCP underlays, where contextual equivalence is typically too strong, due to the need for locking to resolve preemption arising from mobility. [ABSTRACT FROM AUTHOR]

An efficient and secure three-party authenticated key agreement protocol is proposed to enable two users to establish a common secret key for exchanging confidential and authenticated information with the help of a trusted server. The proposed protocol only employs extended chaotic maps and hash operations, i.e., it does not require a server public key, symmetric cryptosystems, time-consuming modular exponential computations, or time-consuming modular exponential computations and scalar multiplications on elliptic curve. A round-efficient version of the proposed protocol is also implemented by rearranging and sending the messages in parallel. The session security of the proposed protocol is based on the Chebyshev chaotic map-based Diffie-Hellman assumption. Compared to related chaotic map-based approaches, the proposed protocol not only requires lower computational cost, but also has fewer transmissions. [ABSTRACT FROM AUTHOR]

Recently, distributed wireless microsensor systems have provided more flexible leverage to emerging industrial applications. The tiny distributed wireless microsensor network systems, however, should be designed to overcome various constraints such as limited energy, bandwidth limit, and unexpected failure of communication under disturbances. In addition, their network topologies need to be managed with designated communication protocols. Thus, design of microsensor network protocols still needs to be application-specific. It should be also evaluated through designated tools at each level of networking characteristics. This research describes essential factors that affect the performance of sensor network systems in the design of wireless microsensor network protocols, and presents effective time-based network protocol and performance evaluation tool which are applicable for various protocols in industrial applications. The developed network evaluation tool, called TIE/MEMS, also includes functional comparison with recent protocols proposed for wireless microsensor networks, and provides design guidelines for multi-sensor network systems needed for emerging industrial applications. [ABSTRACT FROM AUTHOR]

In wireless sensor networks, the goal is to gather information from a large number of sensor nodes and communicate the information to the end-user, all under the constraint of limited energy resources. Network protocols minimize energy by using localized communication and control and by exploiting computation/communication tradeoffs. In addition, data fusion algorithms such as beamforming aggregate data from multiple sources to reduce data redundancy and enhance signal-to-noise ratios, thus further reducing the required communications. We have developed a sensor network system that uses a localized clustering protocol and beamforming data fusion to enable energy-efficient collaboration. We compare the performance of two beamforming algorithms, the Maximum Power and the Least Mean Squares (LMS) beamforming algorithms, using the StrongARM SA-1100 processor. Results show that the LMS algorithm requires less than one-fifth the energy required by the Maximum Power beamforming algorithm with only a 3 dB loss in performance, thus showing that the LMS algorithm is better suited for energy-constrained systems. We explore the energy-scalability of the LMS algorithm, and we propose an energy-quality scalable architecture that incorporates techniques such as variable filter length, variable voltage supply and variable adaptation time. [ABSTRACT FROM AUTHOR]