PSON: A scalable P2P file sharing system with efficient complex query support

A desired P2P file sharing system is expected to achieve the following design goals: scalability, routing efficiency and complex query support. In this paper, we propose a powerful P2P file sharing system, PSON, which can satisfy all the three desired properties. PSON is essentially a semantic overlay network of logical nodes. Each logical node represents a cluster of peers that are close to each other. A powerful peer is selected in each cluster to support query routing on the overlay network while the less powerful peers are responsible for the maintenance of shared contents. To facilitate query routing, super peers are organized in form of a balanced binary search tree. By exploiting the concept of semantics, PSON can support complex queries in a scalable and efficient way. In this paper, we present the basic system design such as the semantic overlay construction, query routing and system dynamics. A load balancing scheme is proposed to further enhance the system performance. By simulation experiments, we show that PSON is scalable, efficient and is able to support complex queries.     

Cooperative caching for multimedia data in mobile P2P networks

Multimedia Tools and Applications - In this paper, we propose a cooperative caching scheme for multimedia data via clusters based on peers connectivity in mobile P2P networks. In the proposed...     

Space efficient secret sharing for implicit data security

This paper presents a k-threshold computational secret sharing technique that distributes a secret S into shares of size , where ∣S∣ denotes the secret size. This bound is close to the space optimal bound of if the secret is to be recovered from k shares. In other words, our technique can be looked upon as a new information dispersal scheme that provides near optimal space efficiency. The proposed scheme makes use of repeated polynomial interpolation and has potential applications in secure information dispersal on the Web and in sensor networks.     

Service and P2P based secure media sharing in mobile commerce environments

Service technology is slowly evolving to be a promising technology for developing applications in open, loosely coupled and distributed computing environments, e.g., in mobile commerce (m-commerce). Services technology can shield the heterogeneous platforms and is suitable for m-commerce applications. Peer-to-Peer (P2P) technology becomes more and more popular for mobile commerce applications. For secure media distribution in m-commerce applications, the security and P2P rights management become more and more urgent. New schemas and architectures for secure P2P based m-commerce applications, which are expected to function automatically or semi-automatically, are expected. In this paper, a secure media service system is presented, which can trace illegal distributors in m-commerce applications. In this scheme, the decryption operation and fingerprint embedding operation are combined together, which avoids the leakage of clear media content in mobile transfer. Additionally, these operations are implemented by the peer, which makes the scheme compliant with existing Peer-to-Peer Digital Rights Management (DRM) systems and very proper for secure media distribution in m-commerce applications. The architectures and modes of secure media distribution in m-commerce environment are presented and discussed.     

ML-Chord: A multi-layered P2P resource sharing model

In recent years, due to the emergence of P2P technology, people rely on the Internet to share resources. It is believed that the number of users and shared resources will become enormously huge. As a result, many researches have been dedicated to improve the scalability and efficiency of P2P models. In this paper, we propose a multi-layered P2P resource sharing model, called ML-Chord, that assigns nodes into Chord-like layers based on the categories of shared resources. From the experimental results, it shows that ML-Chord is both efficient and scalable.     

Modeling resource constrained BitTorrent proxies for energy efficient mobile content sharing

In this paper we present a solution that makes BitTorrent content transfer for mobile device more energy efficient. The main idea of the research is that instead of downloading the content via BitTorrent directly to the mobile phone, an intermediate proxy is used which sends the data to the phone in high speed bursts. This results in smaller energy footprint compared with regular BitTorrent data transfer. Furthermore, we focus on how the proxy can be hosted on memory limited broadband routers which are available in almost every home. We define an analytical model which can be used to analyze the memory allocation strategies of the proxy peers and predict how proxy peers influence the P2P community performance. We verify our model via simulations. We also present measurement results with real life torrents using our prototype system running on home routers and Symbian based mobile phones.     

基于P2P计算的教育资源库共享系统研究

E-learning的有效实施需要将现有异构教育资源库进行集成,提供一个大规模的资源共享平台.深入分析了e-learning对资源共享的目标和教育资源库管理系统的发展趋势,介绍了P2P计算的分类和JXTA开发平台的技术优势.在此基础上,设计了一种混合P2P结构的教育资源库共享系统,给出了基于JXTA平台的系统体系结构与实现方案,详述了利用XML元数据与本体实现数据库与文件资源发布的机制及支持元数据搜索的查询算法.应用P2P技术和本体解决了分布式异构性教育资源的共享问题.     

Ensuring efficient multimedia message sharing in mobile social network

Mobile Social Networks (MSN) are attractive applications which enable users to share data with a group of friends and stay connected. WeChat, QQ are among the most popular applications of MSNs where personal multimedia files are shared among group contacts. However, the security risks accompanying such developments have raised concerns in people. The providers typically store users’ data, and offer few options for the users to custom and manage the dissipation of their data over the network. In this paper, we design a data sharing framework in which individuals retain ownership of their data. The scheme gives users flexible and granular access control over their data, and more importantly it provides protection from the untrusted data provider server. Experiments show the efficiency of our scheme.

     

P2P as a CDN: A new service model for file sharing

Traditional content distribution networks (CDNs), such as Akamai, replicate content at thousands of servers worldwide in an attempt to bring it closer to end users. Recent years have, however, brought a surge of peer-to-peer (p2p) systems that have demonstrated the ability both to help traditional CDN operations and to effectively disseminate content as independent applications. Unfortunately, this p2p surge has created significant problems to network operators by generating large volumes of inter-AS traffic. In this paper, we demonstrate that stepping back and applying traditional CDN design principles to p2p systems can help solve these emerging problems. In particular, focusing on the BitTorrent swarming protocol, we show that our new service model can, in the common case, reduce inter-AS traffic by 45–75%. Moreover, in scenarios when ISPs are shaping inter-AS traffic, it speeds up download times by 60% for the most popular torrents.Our approach bases on disproving the common wisdom that the current peer altruism in p2p systems (BitTorrent in particular) is insufficient. We thus abandon the common approach of deploying novel incentives for cooperation, and focus on designing methods to effectively utilize existing system resources. We show that controlled regional-based content replication, common for the traditional CDN design, can effectively achieve this goal. We implement our system and demonstrate that it effectively scales. Moreover, it is incrementally deployable and brings significant benefits in partial deployment scenarios. ISPs and network regions in which the system gets deployed can resolve their inter-AS traffic problems instantly and autonomously, i.e., without any inter-ISP collaboration and without requiring that the system gets deployed in the entire Internet.     

Adaptive resource scheduling mechanism in P2P file sharing system

Due to the inefficient resource adjustment, the current P2P file sharing systems cannot achieve the balanced relationship between supplements and demands over the resources. In this case, the uploading bandwidth of the system node cannot be utilized efficiently and the overall system QoS is degraded. In this paper, an adaptive resource scheduling mechanism called Push mechanism, is proposed, in which “proactive” strategies are provided to handle the unbalance supplement-demand relationship of some resource. Specifically, the system firstly forecasts which resource will becoming insufficient, then it pre-increase the uploaders over such resource so that the system performance is improved. Through numerical practical experiment in download platform of Tencent, it is proved that the proposed mechanism increases the downloading rate, saves the traffic on the server and optimizes the system performance.     

A continuous reverse skyline query processing scheme for multimedia data sharing in mobile environments

Multimedia Tools and Applications - Recently, various query processing schemes in mobile environments have been studied. Particularly, a reverse skyline query that is the variation of a skyline...     

An efficient server bandwidth costs decreased mechanism towards mobile devices in cloud-assisted P2P-VoD system

Recently, more and more devices with small buffer size such as PDAs or mobile phones are joining in the VoD system, which leads to two major challenges: how to efficiently distribute their bandwidth resources with small buffer size, and how to provide assistant mechanism to make them playback smoothness. In face of this situation and for the purpose of decreasing the server bandwidth costs, we propose a peers’ downloading mechanism called NCDLT to solve above challenges. It contains two algorithms. The first is neighbors and chunks downloading selection (NCS) algorithm and it ensures peers to find neighbors who can provide video data with lower refusal rate. The second is distributed linear taxation algorithm (DLT) and it makes peers with lower capability acquire enough download rate to reduce the request to servers. The simulation results demonstrate that our algorithms can offload the server bandwidth costs and improve the download rate of peers with small buffer size.     

CrowdMed-II: a blockchain-based framework for efficient consent management in health data sharing

World Wide Web - The healthcare industry faces serious problems with health data. Firstly, health data is fragmented and its quality needs to be improved. Data fragmentation means that it is...     

Trustworthy-based efficient data broadcast model for P2P interaction in resource-constrained wireless environments

In a decentralised system like P2P where each individual peers are considerably autonomous, the notion of mutual trust between peers is critical. In addition, when the environment is subject to inherent resource constraints, any efficiency efforts are essentially needed. In light of these two issues, we propose a novel trustworthy-based efficient broadcast scheme in a resource-constrained P2P environment. The trustworthiness is associated with the peer?s reputation. A peer holds a personalised view of reputation towards other peers in four categories namely SpEed, Correctness, qUality, and Risk-freE (SeCuRE). The value of each category constitutes a fraction of the reliability of individual peer. Another factor that contributes to the reliability of a peer is the peer?s credibility concerning trustworthiness in providing recommendation about other peers. Our trust management scheme is applied in conjunction with our trust model in order to detect malicious and collaborative-based malicious peers. Knowledge of trustworthiness among peers is used in our proposed broadcast model named trustworthy-based estafet multi-point relays (TEMPR). This model is designed to minimise the communication overhead between peers while considering the trustworthiness of the peers such that only trustworthy peer may relay messages to other peers. With our approach, each peer is able to disseminate messages in the most efficient and reliable manner.     

A distributed trust management model for mobile P2P networks

In this paper we propose a distributed Trust Management Model (DTMM) for constructing much shorter and more robust trust chains in mobile p2p networks. With DTMM, each moving object within the same group tends to have a high probability of keeping stable distances from each other. The main contribution of this model is to predict the future availability of wireless links and lead to fast generating valid trust evidences. A major difference between DTMM and many existing models in trust literature is that DTMM does not rely on any fixed networking infrastructure, and therefore is able to adapt to both high mobility environments. Our work appears to be the first attempt to research the relationship between mobile patterns and trust management of peers in mobile P2P network. The simulation results show that our model is highly robust and scalable in the dynamic environment of mobile networks.     

BSS: block-based sharing scheme for secure data storage services in mobile cloud environment

For the last few years, academia and research organizations are continuously investigating and resolving the security and privacy issues of mobile cloud computing environment. The additional consideration in designing security services for mobile cloud computing environment should be the resource-constrained mobile devices. The execution of computationally intensive security services on mobile device consumes battery’s charging quickly. In this regard, the study presents a novel energy-efficient block-based sharing scheme that provides confidentiality and integrity services for mobile users in the cloud environment. The block-based sharing scheme is compared with the existing schemes on the basis of energy consumption, CPU utilization, memory utilization, encryption time, decryption time, and turnaround time. The experimental results show that the block-based sharing scheme consumes less energy, reduces the resources utilization, improves response time, and provides better security services to the mobile users in the presence of fully untrusted cloud server(s) as compared to the existing security schemes.     

P2P networking: an information sharing alternative

Peer-to-peer networking offers unique advantages that will make it a more effective alternative to several existing client-server e-commerce applications, if it can mature into a secure and reliable technology. The paper discusses the advantages of P2P networks: load balancing; dynamic information repositories; fault tolerance; content-based addressing and improved searches. It also considers the disadvantages of P2P     

Certificate sharing system for secure certificate distribution in mobile environment

As mobile and Internet technologies evolve, mobile services (e.g., Internet banking, social commerce) continuously expand and diversify. In order to use these mobile services, it is essential that security services, especially distribution certificates (e.g., bank certificates), relevant to mobile devices be provided. Some approaches to providing distribution certificates between a user's mobile device and a personal computer (PC) have been proposed. However, the existing approaches do not guarantee that the certificate in the mobile devices same with the issued one from the PC, causing constraints on mobile services such as mobile phone banking and mobile commerce (M-commerce).In this paper, we propose a novel approach that shares certificates securely without modification of the existing standard certificate format between a smartphone and a PC. We also implemented the certificate sharing system (CSS) in a virtual private network (VPN). The CSS provides strong end-to-end data security for the certificate with a key size of 192-bits which is able to guarantee an expiration date of three years. It also provides strong data security on physical devices with the use of device ID. The certificate that is shared between devices is available only through the CSS's authorization process. In addition, the CSS provides a flexible and extensible system for sharing certificates in enterprise environments. The CSS module of a PC was implemented by way of a standard web language, and the CSS module of a smartphone was developed with the assistance of mobile applications with a small size of 1210KB.     

An energy efficient privacy-preserving content sharing scheme in mobile social networks

The rising popularity of mobile social media enables personalization of various content sharing and subscribing services. These two types of services entail serious privacy concerns not only to the confidentiality of shared content, but also to the privacy of end users such as their identities, interests and social relationships. Previous works established on the attribute-based encryption (ABE) can provide fine-grained access control of content. However, practical privacy-preserving content sharing in mobile social networks either incurs great risk of information leaking to unauthorized third parties or suffers from high energy consumption for decrypting privacy-preserving content. Motivated by these issues, this paper proposes a publish–subscribe system with secure proxy decryption (PSSPD) in mobile social networks. First, an effective self-contained privacy-preserving access control method is introduced to protect the confidentiality of the content and the credentials of users. This method is based on ciphertext-policy ABE and public-key encryption with keyword search. After that, a secure proxy decryption mechanism is proposed to reduce the heavy burdens of energy consumption on performing ciphertext decryption at end users. The experimental results demonstrate the efficiency and privacy preservation effectiveness of PSSPD.     

XBridge-Mobile: efficient XML keyword search on mobile web data

Mobile computing over intelligent mobile is affecting human’s habits of obtaining information over Internet, especially keyword search. Most of previous keyword search works are mainly focused on traditional web data sources, in which the performance can be improved by adding more computing power and/or building more offline-computed index. However, it is very challenging to apply the traditional keyword search methods to mobile web-based keyword search because mobile computing has many different features, e.g., frequent disconnections, variety of bandwidths, limited power of mobile devices, limited data size to be downloaded, etc.. To address this challenge, in this paper we design an adaptive mobile-based XML keyword search approach, called XBridge-Mobile, that can derive the semantics of a keyword query and generate a set of effective structured patterns by analyzing the given keyword query and the schemas of XML data sources. Each structured pattern represents one of user’s possible search intentions. The patterns will be firstly sent to the mobile client from web server. And then, the mobile client can select some interested patterns to load the results. By doing this, we can reduce the communication cost a lot between web server and mobile client because only the derived patterns and a few results need to be transferred, not all the keyword search results, by which we can save lots of expenses when the downloaded data is priced. In addition, we can economically maintain the frequent structured pattern queries in the mobile device, which can further reduce the expense of downloading data. At last, we analyze and propose a ranking function to measure the quality of keyword search results, design a set of algorithms to optimize mobile keyword search based on the maintained structured patterns, and present the experimental study of XBridge-Mobile with real XML datasets.