The novelty of the peer-to-peer (P2P) paradigm relies on two main concepts: cooperation among users and resource sharing. There are many applications based on peer-to-peer paradigm, but the most popular one is the file sharing. We can... more
The novelty of the peer-to-peer (P2P) paradigm relies on two main concepts: cooperation among users and resource sharing. There are many applications based on peer-to-peer paradigm, but the most popular one is the file sharing. We can classify the file sharing application into centralized systems, (having a central server), and decentralized systems. Another classification would be structured and unstructured systems,
Abstract Summary form only given. In a broadcasting problem, a message is sent from a source to all the other nodes in the network. Blind flooding is a classical mechanism for broadcasting, where each node retransmits received message to... more
Abstract Summary form only given. In a broadcasting problem, a message is sent from a source to all the other nodes in the network. Blind flooding is a classical mechanism for broadcasting, where each node retransmits received message to all its neighbors. We ...
This paper presents the use of a novel Peer to Peer (P2P) infrastructure in order to provide rapid broad digital content exchange, digital rights protection and efficient transaction management through watermarking technologies. Copyright... more
This paper presents the use of a novel Peer to Peer (P2P) infrastructure in order to provide rapid broad digital content exchange, digital rights protection and efficient transaction management through watermarking technologies. Copyright owners use digital watermarking techniques so as to encrypt copyright information to the content. This information is represented by multiple watermarking keys used, amongst other reasons, for proof of ownership, unique identification and transaction management. Especially for transaction management the watermarking keys used are constantly changing following the content's route from user to user. The challenges for this research are a) the use of P2P technologies for efficient Digital Rights Management (DRM), b) to apply a robust watermarking algorithm to digital content which successfully embeds and detects multiple keys for each use case and c) to successfully maintain consistent the P2P system when watermarking keys are changing during cont...
Today almost all organizations have improved their performance through allowing more information exchange within their organization as well as between their distributers, suppliers, and customers using web support. Databases are central... more
Today almost all organizations have improved their performance through allowing more information exchange within their organization as well as between their distributers, suppliers, and customers using web support. Databases are central to the modern websites as they provide necessary data as well as stores critical information such as user credentials, financial and payment information, company statistics etc. These websites have
In this paper, we propose a Progressive Differential Thresholding (PDT) framework for coordinated network anomaly detection. Under the proposed framework, nodes present on a packet's path progressively encode their opinion (malicious or... more
In this paper, we propose a Progressive Differential Thresholding (PDT) framework for coordinated network anomaly detection. Under the proposed framework, nodes present on a packet's path progressively encode their opinion (malicious or benign) inside a packet. Subsequent nodes on the path use the encoded opinion as side-information to adapt their anomaly detection thresholds and in turn improve their classification accuracies. Accuracy benefits of PDT are evaluated through experimental evaluations of multiple non-proprietary anomaly detectors on a publicly-available attack dataset. These evaluations indicate that, while being distributed and having negligible complexity and communication overheads, the proposed PDT framework provides considerable and consistent improvements in anomaly detection accuracy. We observe upto 54% improvements in ADS detection accuracy while upto 4 times reduction in the false alarm rates.
In mobile IP based networks, most of the packet drops occur due to mobile handoff from one sub-network to another sub-network or larger delays in between sender and receiver due to encapsulation and tunnelling of packets. Packet loss... more
In mobile IP based networks, most of the packet drops occur due to mobile handoff from one sub-network to another sub-network or larger delays in between sender and receiver due to encapsulation and tunnelling of packets. Packet loss during the handoff operation in mobile IP with route optimization and smooth handover will degrade the performance of Transmission Control Protocol (TCP). To prevent performance degradation due to mobile handover packet drops, a number of packet buffering and packet forwarding mechanisms have been proposed. However, mobile user continually change its point-of-attachment and can sometimes move into congested base station of foreign agent sub network, its buffered forwarded packets are likely to be dropped at the new base station. This can lead to decrease in congestion window size at the sender TCP, which will severely degrade the performance of TCP even though there is no congestion within the network. In this approach, hardware resources (packet buffers) are efficiently utilized, at the same time performance degradation of TCP due to congested base station of current mobile node is minimized through packet buffers, markers and with modification in Mobile IP binding update message.
In this paper, we propose a decentralized self-adaptive management framework that infers the current context of the hosting environment and dynamically decides what management strategy should be used in order to minimize the cost and... more
In this paper, we propose a decentralized self-adaptive management framework that infers the current context of the hosting environment and dynamically decides what management strategy should be used in order to minimize the cost and maximize the performance of management. We investigate the use of this framework in the case of the aggregated information monitoring, where only one scheme (i.e. situated or global) is generally used for collecting aggregated information whatever the nature of the management information and its environment are. We propose a self-adaptive aggregation mechanism based on fuzzy logic, that estimates the cost and the performance of given aggregation schemes.
The phenomenon of churn degrades the lookup performance of DHT-based P2P systems greatly. To date, a number of approaches have been proposed to handle it from both the system side and the client side. However, there lacks theoretical... more
The phenomenon of churn degrades the lookup performance of DHT-based P2P systems greatly. To date, a number of approaches have been proposed to handle it from both the system side and the client side. However, there lacks theoretical analysis to direct how to make design choices under different churn levels and how to configure their parameters optimally. In this paper, we analytically study three important aspects on improving DHT lookup performance under churn, ie, lookup strategy, lookup parallelism ...
The information-centric networking (ICN) concept is a significant common approach of several future Internet research activities. The approach leverages in-network caching, multiparty communication through replication, and interaction... more
The information-centric networking (ICN) concept is a significant common approach of several future Internet research activities. The approach leverages in-network caching, multiparty communication through replication, and interaction models decoupling senders and receivers. The goal is to provide a network infrastructure service that is better suited to today¿s use (in particular. content distribution and mobility) and more resilient to disruptions and
In this paper we address the problem of efficient layered video streaming over peer-to-peer networks and we propose a new receiver-driven streaming mechanism. The main design goal of our new layered video requesting policy is to optimize... more
In this paper we address the problem of efficient layered video streaming over peer-to-peer networks and we propose a new receiver-driven streaming mechanism. The main design goal of our new layered video requesting policy is to optimize the overall distribution of video streams in terms of reliability and overhead. Since the layered peer-to-peer streaming problem is NP-Hard, we show that the classic approaches widely used in layered P2P streaming systems have some limitations and we propose an optimization technique based on harmony search which aims at increasing the rate of successful data transmissions for the most important video layers, while reducing the protocol overhead and ensuring load balancing among the participating peers. Analytical results have demonstrated that our new requesting policy enhances the streaming of layered video over mesh-based peer-to-peer networks and outperforms classic approaches.
The common goals of the Grid and peer-to-peer communi- ties have brought them in close proximity. Both the technologies overlay a collaborative resource-sharing infrastructure on existing (public) net- works. In realizing this shared... more
The common goals of the Grid and peer-to-peer communi- ties have brought them in close proximity. Both the technologies overlay a collaborative resource-sharing infrastructure on existing (public) net- works. In realizing this shared goal, however, they concentrate on signif- icantly contrasting issues. The Grid paradigm focuses on performance, control, security, specialization, and standardization. On the other hand, the peer-to-peer paradigm
We aim to support spontaneous and opportunistic human behavior by taking advantage of an emerging environment for mobile ubiquitous multimedia applications enabled by the fusion of adhoc networks, peer-to-peer computing, and media-rich... more
We aim to support spontaneous and opportunistic human behavior by taking advantage of an emerging environment for mobile ubiquitous multimedia applications enabled by the fusion of adhoc networks, peer-to-peer computing, and media-rich mobile ...
This paper addresses issues pertaining to the necessity of uti- lizing formal verification methods in the design of protocols for peer-to-peer multimedia systems. These systems require sophisticated communication protocols, and these... more
This paper addresses issues pertaining to the necessity of uti- lizing formal verification methods in the design of protocols for peer-to-peer multimedia systems. These systems require sophisticated communication protocols, and these protocols require verification. We discuss two sample protocols de- signed for two distinct peer-to-peer computer vision appli- cations, namely multi-object multi-camera tracking and dis- tributed gesture recognition. We present
EigenTrust (ET) is a renowned algorithm for reputation management in adversarial P2P systems. It incorporates the opinions of all peers in the network to compute a global trust score for each peer based on its past behavior, and relies on... more
EigenTrust (ET) is a renowned algorithm for reputation management in adversarial P2P systems. It incorporates the opinions of all peers in the network to compute a global trust score for each peer based on its past behavior, and relies on a set of pre-trusted nodes to guarantee that malicious nodes cannot subvert the system. In this paper, we show that ET is vulnerable to community structure and a novel targeted attack based on eigenvector centrality, since ET ranks nodes close to the pre-trusted ones higher than those further away. To address these shortcomings, we propose Personalized EigenTrust (PET) which (i) enables each user to choose her trusted peers from the social network of peers, thereby eliminating the need of pre-trusted nodes and making the system autonomous, (ii) is effective in networks operating under various transaction models based on distributions such as random, community-like and power-law, and (iii) is robust to many types of attacks including the targeted one based on eigenvector centrality. Our simulation results reveal that PET outperforms ET under diverse transaction models and attack strategies.