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Fiandrotti A.,Sisvel Technology | Gaeta R.,University of Turin | Grangetto M.,University of Turin
IEEE Transactions on Multimedia | Year: 2015

Network coding (NC)-based peer-to-peer (P2P) streaming represents an effective solution to aggregate user capacities and to increase system throughput in live multimedia streaming. Nonetheless, such systems are vulnerable to pollution attacks where a handful of malicious peers can disrupt the communication by transmitting just a few bogus packets which are then recombined and relayed by unaware honest nodes, further spreading the pollution over the network. Whereas previous research focused on malicious nodes identification schemes and pollution-resilient coding, in this paper we show pollution countermeasures which make a standard NC scheme resilient to pollution attacks. Thanks to a simple yet effective analytical model of a reference node collecting packets by malicious and honest neighbors, we demonstrate that: i) packets received earlier are less likely to be polluted, and ii) short generations increase the likelihood to recover a clean generation. Therefore, we propose a recombination scheme where nodes draw packets to be recombined according to their age in the input queue, paired with a decoding scheme able to detect the reception of polluted packets early in the decoding process and short generations. The effectiveness of our approach is experimentally evaluated in a real system we developed and deployed on hundreds to thousands of peers. Experimental evidence shows that, thanks to our simple countermeasures, the effect of a pollution attack is almost canceled and the video quality experienced by the peers is comparable to pre-attack levels. © 2015 IEEE. Source


Fiandrotti A.,Sisvel Technology | Gaeta R.,University of Turin | Grangetto M.,University of Turin
Proceedings - IEEE International Conference on Multimedia and Expo | Year: 2015

Band Codes (BC) have been recently proposed as a solution for controlled-complexity random Network Coding (NC) in mobile applications, where energy consumption is a major concern. In this paper, we investigate the potential of BC in a peer-to-peer video streaming scenario where malicious and honest nodes coexists. Malicious nodes launch the so called pollution attack by randomly modifying the content of the coded packets they forward to downstream nodes, preventing honest nodes from correctly recovering the video stream. Whereas in much of the related literature this type of attack is addressed by identifying and isolating the malicious nodes, in this work we propose to address it by adaptively adjusting the coding scheme so to introduce resilience against pollution propagation. We experimentally show the impact of a pollution attack in a defenseless system and in a system where the coding parameters of BC are adaptively modulated following the discovery of polluted packets in the network. We observe that just by tuning the coding parameters, it is possible to reduce the impact of a pollution attack and restore the quality of the video communication. © 2015 IEEE. Source


Fiandrotti A.,Sisvel Technology | Gaeta R.,University of Turin | Grangetto M.,University of Turin
IEEE Transactions on Multimedia | Year: 2016

We provide a comprehensive characterization of band codes (BC) as a resilient-by-design solution to pollution attacks in network coding (NC)-based peer-To-peer live video streaming. Consider one malicious node injecting bogus coded packets into the network: The recombinations at the nodes generate an avalanche of novel coded bogus packets. Therefore, the malicious node can cripple the communication by injecting into the network only a handful of polluted packets. Pollution attacks are typically addressed by identifying and isolating the malicious nodes from the network. Pollution detection is, however, not straightforward in NC as the nodes exchange coded packets. Similarly, malicious nodes identification is complicated by the ambiguity between malicious nodes and nodes that have involuntarily relayed polluted packets. This paper addresses pollution attacks through a radically different approach which relies on BCs. BCs are a family of rateless codes originally designed for controlling the NC decoding complexity in mobile applications. Here, we exploit BCs for the totally different purpose of recombining the packets at the nodes so to avoid that the pollution propagates by adaptively adjusting the coding parameters. Our streaming experiments show that BCs curb the propagation of the pollution and restore the quality of the distributed video stream. © 1999-2012 IEEE. Source


Ballocca G.,Sisvel Technology | Fiandrotti A.,Sisvel Technology | Mattelliano M.,Sisvel Technology | Mosca A.,Sisvel Technology
2014 IEEE International Conference on Image Processing, ICIP 2014 | Year: 2014

The MPEG CDVS (Compact Descriptors for Visual Search) standard promises to enable effective, bandwidth-efficient, image matching and retrieval. In this paper, we describe the issues related to the implementation of such technology in an app for smartphones and demonstrate its application to the problem of guiding a tourist through a urban photo safari. To the best of our knowledge, this work is also the first to provide preliminary figures of CDVS performance on a mobile device. © 2014 IEEE. Source

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