Short signature scheme for multi-source network coding

With the emergence of vehicular Internet-of-Things (IoT) applications, it is a significant challenge for vehicular IoT systems to obtain higher throughput in vehicle-to-cloud multipath transmission. Network Coding (NC) has been recognized as a promising paradigm for improving vehicular wireless network throughput by reducing packet loss in transmission. However, existing researches on NC do not consider the influence of the rapid quality change of wireless links on NC schemes, which poses a great challenge to dynamically adjust the coding rate according to the variation of link quality in vehicle-to-cloud multipath transmission in order to avoid consuming unnecessary bandwidth resources and to increase network throughput. Therefore, we propose an Adaptive Network Coding (ANC) scheme brought by the novel integration of the Hidden Markov Model (HMM) into the NC scheme to efficiently adjust the coding rate according to the estimated packet loss rate (PLR). The ANC scheme conquers the rapid change of wireless link quality to obtain the utmost throughput and reduce the packet loss in transmission. In terms of the throughput performance, the simulations and real experiment results show that the ANC scheme outperforms state-of-the-art NC schemes for vehicular wireless multipath transmission in vehicular IoT systems.

This paper presents an efficient data gathering framework of network coding (NC) coupled compressed sensing (CS) in wireless sensor networks (WSNs), called network compressed coding (NCC). We employ network coding to adapt to the dynamic nature of WSNs, such as moving obstacles and link failure. Measurements from sensor networks are often correlated because sensors nodes nearby observe the contiguous phenomenon, and the operation of the random linear network coding (RLNC) scheme is similar to that of the random projection in compressed sensing. Therefore, we introduce compressed sensing into the network coding (NC), to prevent all-or-nothing impact on NC. NCC simultaneously transmits and encodes specific packets of sensor measurements to form random projections for CS recovery. CS technology guarantees that the data gathered at all nodes are accurately recovered with a high probability from a small number of projections, which is less than the total number of source nodes in the network. Our simulation results show that, only less than half number of packets are required to reconstruct measurements with reasonable quality compared with the traditional network coding schemes. Also, NCC increases the data gathering efficiency by over 20% compared to the conventional NC scheme.

We propose a novel linear physical-layer network coding (NC) scheme for a fading Y-channel without channel state information at transmitters. In this three-user scheme, each user intends to realize a full data exchange with the other two users via a relay. Instead of directly decoding the users' messages from the received signal, the relay determines NC generator matrices and reconstructs linear NC codewords from its received signals to facilitate the information exchange. We present an explicit solution for NC generator matrices that minimize the NC error probability at high SNRs. We also present and prove an approximation of the NC error probability of the proposed scheme at high SNRs. Numerical results show that the proposed scheme outperforms existing ones, and its performance can be well characterized by the approximation.

Recent studies show that network coding can provide significant benefits to network protocols, such as increased throughput, reduced network congestion, higher reliability, and lower power consumption. The core principle of network coding is that intermediate nodes actively mix input packets to produce output packets. This mixing subjects network coding systems to a severe security threat, known as a \emph{pollution attack}, where attacker nodes inject corrupted packets into the network. Corrupted packets propagate in an epidemic manner, depleting network resources and significantly decreasing throughput. Pollution attacks are particularly dangerous in wireless networks, where attackers can easily inject packets or compromise devices due to the increased network vulnerability.In this paper, we address pollution attacks against network coding systems in wireless mesh networks. We demonstrate that previous solutions to the problem are impractical in wireless networks, incurring an unacceptably high degradation of throughput. We propose a lightweight scheme, DART, that uses time-based authentication in combination with random linear transformations to defend against pollution attacks. We further improve system performance and propose EDART, which enhances DART with an optimistic forwarding scheme. A detailed security analysis shows that the probability of a polluted packet passing our verification procedure is very low. Performance results using the well-known MORE protocol and realistic link quality measurements from the Roofnet experimental testbed show that our schemes improve system performance over 20 times compared to previous solutions.

Network coding has been shown to be useful for throughput and reliability in various network topologies, under a fixed-rate, point-to-multipoint wireless network model. We study the effect of introducing a wireless network model where link capacity depends on the network geometry and the signal to interference and noise ratio. In particular, we compare strategies with and without network coding on a multicast network with and without fading, and on single-user multiple path networks with fading. For the multicast network without fading, we find that the network geometry affects which scheme attains higher throughput. For the case with fading, we compare the throughput-outage probability curves achieved by network coding and repetition schemes. For the multiple path networks, we further consider the case where multiple simultaneous transmissions of identical information signals can be combined at a receiver. We find that the relative performance of the schemes we consider depends on the network geometry, the ratio of signal to noise power, whether multiple simultaneous transmissions can be combined, and the operating point on the throughput-outage probability curve

The network coding usually suffers from pollution attacks. Two schemes against pollution attacks are discussed in this paper, based on linear space signature and information theory, respectively. Pollution attacks detection algorithm of information theory based scheme is improved. The time consumptions of two schemes under different conditions of file size and data segmentation size are compared, and then a new scheme combining linear space signature and with information theory is provide to fight pollution attacks.

This paper studies non-orthogonal transmission over a $K$ -user fading multiple access channel. We propose a new reliable physical-layer network coding and cascade-computation decoding scheme. In the proposed scheme, $K$ single-antenna users encode their messages by the same practical channel code and QAM modulation, and transmit simultaneously. The receiver chooses $K$ linear coefficient vectors and computes the associated $K$ layers of finite-field linear message combinations in a cascade manner. Finally, the $K$ users’ messages are recovered by solving the $K$ linear equations. The proposed can be regarded as a generalized onion peeling. We study the optimal network coding coefficient vectors used in the cascade computation. Numerical results show the performance of the proposed approaches that of the iterative maximum $a~posteriori$ probability detection and decoding scheme, but without using receiver iteration. This results in considerable complexity reduction, processing delay, and easier implementation. Our proposed scheme significantly outperforms the iterative detection and decoding scheme with a single iteration, for example, by 1.7 dB for the two user case. The proposed scheme provides a competitive solution for non-orthogonal multiple access.

As one of the emerging technologies with most potential for developing, Network Coding (NC) has gained significant momentum. Due to encode-and-forward model, NC has natural privacy in communication, but it also induces that attackers become more imperceptible and impact on NC caused by them becomes more far-reaching. This requires that the security schemes should consider the characteristics of different attacks in NC. In this paper, we provide a survey of secure network coding toward various attacks. First of all, we summarize four types of representative attacks in NC system including entropy attack, Byzantine attack, pollution attack and eavesdropping attack, and compare the differences of these attacks between in traditional store-and-forward mode and network coding mode. Secondly, we give a comprehensive investigation of numerous defense approaches and mechanisms classified by these attacks. Finally, for stimulating stream of thoughts about secure network coding schemes, several open issues are proposed and discussed.

Network coding allows intermediate nodes to encode data packets to improve network throughput and robustness. However, it increases the propagation speed of polluted data packets if a malicious node injects fake data packets into the network, which degrades the bandwidth efficiency greatly and leads to incorrect decoding at sinks. In this paper, insights on new mathematical relations in linear network coding are presented and a key predistribution-based tag encoding scheme KEPTE is proposed, which enables all intermediate nodes and sinks to detect the correctness of the received data packets. Furthermore, the security of KEPTE with regard to pollution attack and tag pollution attack is quantitatively analyzed. The performance of KEPTE is competitive in terms of: low computational complexity; the ability that all intermediate nodes and sinks detect pollution attack; the ability that all intermediate nodes and sinks detect tag pollution attack; and high fault-tolerance ability. To the best of our knowledge, the existing key predistribution-based schemes aiming at pollution detection can only achieve at most three points as described above. Finally, discussions on the application of KEPTE to practical network coding are also presented.

In network system, network coding allows intermediate nodes to encode the received messages before forwarding them, thus network coding is vulnerable to pollution attacks. Besides, the attacks are amplified by the network coding process with the result that the whole network maybe pollutes. In this paper, we proposed a novel unconditionally secure authentication code for multi-source network coding, which is robust against pollution attacks. For the authentication scheme based on theoretic strength, it is robust against those attackers that have unlimited computational resources, and the intermediate nodes therein can verify the integrity and origin of the encoded messages received without having to decode them, and the receiver nodes can check them out and discard the messages that fail the verification. By this way, the pollution is canceled out before reaching the destinations.

Cooperative communication is shown to be an efficient method of combating fading in wireless networks. By ”sharing” their antennas cooperating single-antenna nodes create a virtual multi-antenna system and therefore, benefit from spatial diversity. Network coding being a particular cooperative communication technique provides substantial gains in data rate, especially in networks with many sink nodes. By allowing intermediate nodes of a network to mix the incoming data streams, one can achieve the multicast capacity. Recently, Xiao and Skoglund showed that binary network coding (BNC) is not optimal for multi-user multi-relay networks in terms of diversity and proposed diversity network coding (DNC) scheme that outperforms BNC approach. Following this approach we examine potential diversity gains of using the DNC scheme for multi-source line networks. We show that the DNC technique outperforms both conventional time-orthogonal transmission and the BNC scheme. Further, the problem of optimal scheduling of the transmission is explored. We formulate the optimization problem and propose efficient solutions. Numerical results are presented to support theoretical findings.

Network coding (NC)-enabled mobile small cells are observed as a promising technology for fifth-generation (5G) networks that can cover the urban landscape by being set up on-demand at any place and at any time on any device. Nevertheless, despite the significant benefits that this technology brings to the 5G of mobile networks, major security issues arise due to the fact that NC-enabled mobile small cells are susceptible to pollution attacks; a severe security threat exploiting the inherent vulnerabilities of NC. Therefore, intrusion detection and prevention mechanisms to detect and mitigate pollution attacks are of utmost importance so that NC-enabled mobile small cells can reach their full potential. Thus, in this article, we propose for the first time, to the best of our knowledge, a novel intrusion detection and prevention scheme (IDPS) for NC-enabled mobile small cells. The proposed scheme is based on a null space-based homomorphic message authentication code (MAC) scheme that allows detection of pollution attacks and takes proper risk mitigation actions when an intrusive incident is detected. The proposed scheme has been implemented in Kodo and its performance has been evaluated in terms of computational overhead.

Content distribution system can transmit large files rapidly between multiple users, and it has become the most widely used in internet. Network coding is a technique which can enhance the performance and reliability of P2P networks. P2P content distribution networks can suffer from malicious participants that corrupt content. Existing systems verify distributed blocks of file with conventional encryption techniques and hash functions. However, these techniques do not apply well to more well-designed schemes that use network coding techniques for efficient content distribution. In such networks, it is necessary that some security mechanisms will be applied with the aim of avoiding attacks based on non authorized content modifications. Some threats like pollution attack, entropy attack, jamming attack degrade the performance of content delivery in P2P networks. To identify the polluted blocks is difficult and needs the use of homomorphic hashing functions, whose implementation is expensive. This paper review a security scheme for network coding that reduces the cost of verifying blocks on the way before decoding while efficiently preventing the propagation of malicious blocks. In this scheme, users not only cooperate to distribute the content, but users also cooperate to protect themselves against malicious users by informing affected nodes when a malicious block is found. In this paper we analyze and study such cooperative security schemes.

In this paper, a vertical physical-layer network coding (VPNC) scheme based pulse amplitude modulation (PAM) for two-way relay channel (TWRC) is proposed. Different from the conventional physical layer network coding (PNC) scheme in which the relay superimposes two users' signals of the same constellation, in the proposed VPNC scheme two users transmit PAM signals with vertical constellation and the relay superimposes two signals of vertical constellation in the multiple access (MA) phase. In addition, when the VPNC is exploited in conjunction with channel coding, joint channel VPNC is proposed to further improve the BER performance. Simulation results show that the proposed VPNC scheme outperforms the conventional PNC scheme on BER performance.

Excessive padding overhead induced by packets of heterogeneous lengths is a critical problem when using network coding for real-world data in the wild. Current network coding schemes either use excessive zero-padding or communication-intensive packet reconstruction strategies, i.e. bundling or chaining. This paper presents novel encoding strategies to reduce the padding-induced overhead while preserving the original packet structures. The conducted evaluation is based on traces of datagram-based real-world applications, namely browsing via QUIC, Skype VoIP, FFmpeg video streaming, and UFTP file transfer. The results verify that the packet-preserving coding schemes can significantly reduce the overhead of transmitted bytes for different generation sizes and packet loss rates without the need for additional communication about packet reconstruction.