A Trust Scheme Based DRM Model for P2P System

With the maturation of P2P technology, there are more and more challenges to the protection of digital rights. DRM for traditional Client/Server model can not satisfy the requirement of digital right protection of P2P network. With practical application of P2P network technology and new generational DRM technology, the article proposes a DRM model for P2P system based on trust degree. The proposed model shares the secret key to the trusty peers and affords necessary security ensure for digital content delivery based on P2P technology. Mathematic analyses and simulations show that, compared to the current DRM model, the proposed model is more robust toleration of transmit and security.

HICUS:A QUASI-STRUCTURED P2P SYSTEM BASED ON HIERARCHICAL INTEREST

The key problem in unstructured P2P system is how to control "Flood".Some studies focus on constructing more efficient topology while others focus on better query algorithms.This paper presents HICUS(Hierarchical Interest-driven Community-based Unstructured System) motivated by a basic thought-whether the resources correlate with topology distinguishes structured and unstruc-tured P2P essentially.By introducing hierarchical "interest",HICUS organizes a quasi-structured topology through a pure distributed way,and provides a new platform for query algorithms.We study the procedure and performance of topology organization,and the simulations show that HICUS forms a small-world which can significantly improve the routing efficiency.

电力P2P交易中计及社会福利的产消者合作联盟

随着分布式清洁能源发电技术的发展,传统电力用户逐渐转变为电能产消者,并可采用合作联盟形式参与电力P2P(peer to peer)交易,促进分布式清洁能源就地消纳。该文通过从源端和传输端分别核算碳减排量的方法,构建一类考虑经济效益和环境效益的社会福利函数,研究分布式电能产消者通过合作联盟形式实现社会福利最大化的途径。设计一种依据产消者对联盟社会福利贡献值分配合作剩余的机制,激励产消者合作的积极性以维持联盟的稳定。算例分析表明:相较于P2G(peer-to-grid)交易和非合作P2P交易,产消者以合作联盟方式参与电力P2P交易的社会福利分别提升了62.62%、33.79%。因此,以市场化的方式组建合作联盟参与电力P2P交易并合理分配利益,可挖掘分布式清洁能源就地消纳的潜力,促进能源消费的绿色低碳转型。

Research and Development of Multimedia Teaching Management System Based on SIP ＆ P2P

Multimedia teaching managemem system based on SIP ＆ P2P is proposed on account of the existing deficiency on video teaching of distance education. The designed P2P-SIP system applies SIP protocol to realize the underlying DHT, which guarantees zero-configuration, robustness and adaptability in P2P system. And maximum improvement in performance of the networks for multimedia system can be implemented by rapid networking and information sharing technology of the underlying P2P networks as well as fast call and location technology of SIP system. Experiments indicates that multimedia teaching management system based on SIP ＆ P2P could meet the requirement of system design on data latency and calling location.

基于灵活性资源调节和网络重构的P2P交易的阻塞管理方法

高渗透率可再生能源接入配电网不仅促进了分布式电源以端对端(peertopeer,P2P)的形式参与市场交易,也对电网的安全稳定运行提出了挑战。针对连续双向拍卖(continuous double auction,CDA)机制下P2P交易所导致的阻塞问题,提出了一种考虑产消者经济性的P2P能量市场和阻塞服务市场相互协调的机制和阻塞管理方法。首先,为实现产消者的合理定责,提出了一种考虑交易时序的阻塞定责方式。然后,考虑到产消者参与P2P能量市场和阻塞服务市场的经济性,建立了考虑两级市场产消者经济性的灵活性资源阻塞服务价格模型。在上述基础上,建立了基于网络重构和灵活性资源调节的P2P交易阻塞管理模型。最后,通过具体算例分析了安全校核结果和阻塞管理结果,并验证了所提阻塞方法的可行性和优越性。

计及P2P市场产消者灵活性的配电网阻塞管理

多点接入的柔性负荷和可再生分布式电源会使配网潮流大小和方向频繁变动,而配电侧产消者通常仅考虑自身效益最大为目标进行端对端(peer-to-peer,P2P)电能交易,忽略了不同设备能量流动对系统安全运行的影响,使得交易结果极易导致网络阻塞。针对采用连续双向拍卖机制和零智商增强型投标策略的分散式P2P交易模式所引起的配网阻塞,兼顾产消者数据隐私管理和消费心理学影响,提出一种两级市场动态协调阻塞管理方法。该方法以产消者综合效益最大和解决网络阻塞调节量最小为目标,利用Distflow潮流模型,构建基于节点边际电价的节点灵活性辅助服务价格计算模型。进而通过分布式优化算法求解得到阻塞成本,将该成本按照P2P交易时序和线路阻塞贡献度分摊至有责任的产消者,实现阻塞消除。算例采用IEEE 33节点改进的11节点配网系统,结果表明该方法可在设定的时间尺度和计算精度条件下有效解决网络阻塞,降低阻塞成本和分散式P2P电能交易的效益损失。

基于区块链技术的P2P网络分布式数字签名系统设计

随着互联网技术的不断发展,数字签名技术已成为网络安全领域的重要保障之一。然而,传统的集中式数字签名系统存在着单点故障、性能瓶颈等问题。为了解决这些问题,文章设计了一种基于区块链技术的P2P网络分布式数字签名系统。该系统采用区块链技术来实现数字签名的验证和存储,同时利用P2P网络的特性来进行数字签名的分发和共享。实验分析结果表明,本系统不仅具有高度的安全性和可靠性,还能够提高数字签名的效率和可用性。

Continually Answering Constraint k-NN Queries in Unstructured P2P Systems

We consider the problem of efficiently computing distributed geographical k-NN queries in an unstructured peer-to-peer （P2P） system, in which each peer is managed by an individual organization and can only communicate with its logical neighboring peers. Such queries are based on local filter query statistics, and require as less communication cost as possible which makes it more difficult than the existing distributed k-NN queries. Especially, we hope to reduce candidate peers and degrade communication cost. In this paper, we propose an efficient pruning technique to minimize the number of candidate peers to be processed to answer the k-NN queries. Our approach is especially suitable for continuous k-NN queries when updating peers, including changing ranges of peers, dynamically leaving or joining peers, and updating data in a peer. In addition, simulation results show that the proposed approach outperforms the existing Minimum Bounding Rectangle （MBR）-based query approaches, especially for continuous queries.

Design and Implementation on the P2P VOD System Based on the RF-IPS Algorithm

This paper presents a P2P VOD system based on RF-IPS algorithm, and this system consists of two parts, server-side and clients. We put emphasis on the piece selection module of server-side, and in this part we cite the RF-IPS algorithm proposed in the past. In the piece selection module, we also proposed a weighting function except the RF-IPS algorithm. Using this function we will find the best server peers effectively and quickly, it will enhance the performance of this system. We carry on experiments on RF-IPS algorithm, and the results show this algorithm is efficient. Overall, we believe that the RF-IPS algorithm is feasible to further improve system performance and provide a cost-effective P2P VOD service with acceptable user experience.

Designing a Security Architecture for a P2P Video Conference System

More and more modern group oriented collaborativeapplications use the peer-to-peer(P2P)paradigm tobe independent of expensive infrastructures as theyare,for instance,provided for audio and video conferencesby H.323 systems.Decentralized collaborativeP2P solutions require appropriate mechanismsto protect group privacy and data integrity.A centralizedclient/server based video conference system canbe well shielded in a standard manner,whilst thereare no off-the-shelf approaches to secure a P2P videoconference up to now.The paper addresses this issueand presents a flexible security architecture.Usingthe BRAVIS system[4]as an example it shows howthe architecture can be embedded into a P2P videoconferencing system.

A Motivate Mechanism for Large-Scale P2P Content Delivery System

For lack of effective resource adjustment method, the supply-demand relationship of each resource in P2P content delivery system are often unbalanced. Especially after a popular content releasing, a burst of downloaders often can＇t find sufficient uploaders and their request may starve the upload capacity of server. Therefore the overall system QoS may be degraded. To tackle such issue, this paper proposes a download rate accelerate mechanism, called motivate mechanism. With it, the system can quickly find out the files becoming insufficient by monitoring the operating status of the files hourly, Then it promptly increase the number of copies of those files by using free rider nodes so that the whole system QoS is maintained and the system performance is improved. The experiment results on the practical operating system of Tencent demonstrated that the proposed mechanism increases the download rate, saves the traffic on the server and optimizes the system performance.

Peer selecting model based on FCM for wireless distributed P2P files sharing systems

IIn order to improve the performance of wireless distributed peer-to-peer(P2P)files sharing systems,a general system architecture and a novel peer selecting model based on fuzzy cognitive maps(FCM)are proposed in this paper.The new model provides an effective approach on choosing an optimal peer from several resource discovering results for the best file transfer.Compared with the traditional min-hops scheme that uses hops as the only selecting criterion,the proposed model uses FCM to investigate the complex relationships among various relative factors in wireless environments and gives an overall evaluation score on the candidate.It also has strong scalability for being independent of specified P2P resource discovering protocols.Furthermore,a complete implementation is explained in concrete modules.The simulation results show that the proposed model is effective and feasible compared with min-hops scheme,with the success transfer rate increased by at least 20% and transfer time improved as high as 34%.

HitPeers:A P2P File Sharing System with Category Tree

HitPeers conotitute a scalable and highly efficient P2P file sharing system in which all the data file can be shared. The center of HitPeers is the Category Tree (CT). CT collects the published information with category. It is flexible enough to let users customize their own local CT. Its hierarchy helps users to find the information they desire most conveniently. To increase the robustness and retain the efficiency, HitPeers will divide the tree into disjoint parts. Every part is a subtree. Some special nodes named Onodes will take charge of the subtree and play the role of a service provider. HitPeers produce more and more Onodes to meet the service demands in the internet scale distributed environment. This paper will show the profile of the whole system.

Search by shortcuts in P2P scientific collaboration system

A P2P scientific collaboration is a P2P network whose members can share documents, co-compile papers and codes, and communicate with each other instantly. From the simulation experiment we found that P2P collaboration system is a power-law network with a tail between -2 and -3.We utilized the algorithm that searches by high-degree shortcuts to improve the scalability of p2p collaboration system. The experimental result shows that the algorithm works better than random walk algorithm.

基于P2P的碳市场交易模型及电碳联合出清方法

围绕电力行业的低碳发展需求,针对目前电力市场和碳市场所存在未能协调运行的问题,设计一种电碳联合P2P交易机制,通过引入电力P2P交易,给予用户和发电商调动自身灵活性的空间,为火电企业提供碳减排服务的同时,促进新能源消纳,提高各参与主体的效益。同时,分析了传统电力市场以及在引入P2P交易和碳市场机制的交易模式下参与主体的效益变化情况。根据设计机制的需求,建立电碳联合市场出清模型,并通过设计算例进行模拟,分析该交易机制的可行性和有效性。

基于ADMM的完全去中心化P2P能源交易机制

为研究完全去中心化的点对点(peer-to-peer,P2P)能源市场中产消者的最优清算问题,重点解决产消者内部的协作和在P2P市场中实现社会福利最大化的挑战,采用了一种新的平行、分布式的交替方向乘子法(alternating direction method of multipliers,ADMM),推导出P2P市场的交易机制。该方法考虑每个产消者的效用函数,并引入分布式发电机(distributed generator,DG)和电能存储系统(battery energy storage system,BESS)。算法中每个产消者通过迭代与其相邻的产消者同步交换少量信息,并优化以满足不同的需求。通过对6-peers系统的数值验证,证明了所提出方法的有效性。与基于池的交易机制相比,完全去中心化的P2P问题在单位时间内交易电量提升了160%,社会福利从-9.47元增加到32.43元。

Auto Distribution of Tag Table in P2P Control System

In control system, tag table is like a dictionary mapping tagname to address. Therefore, applications on workstation may use tagname to access different data in system. Normally tag table generated by configuration software will transfer to other workstation in system manually after system configuration, which is inconvenient and failible. The development of peer-to-peer （P2P） network technology and the realization of control system based on P2P network make the auto distn＇bution of tag table possible. In this paper based on file sharing technology the presented method realizes the auto distn＇bution of tag table.

A Novel Approach to Improve the Security of P2P File-Sharing Systems

The recent and unprecedented surge of public interest in peer-to-peer (P2P) file-sharing systems has led to a variety of interesting research questions. How to minimize threats in such an open community is an impor-tant research topic. Trust models have been widely used in estimating the trustworthiness of peers in P2P file-sharing systems where peers can transact with each other without prior experience. However, current P2P trust models almost take no consideration for the nature of trust, fuzzy, complex and dynamic, which results in low efficiency in resisting the attacks of malicious nodes. In this paper, a new trust model named NatureTrust that can alleviate the shortage brought by the nature of trust is proposed. In order to cope with the fuzzy characteristic of trust, linguistic terms are used to express trust. Additionally, fuzzy inference rules are employed to evaluate trust of each transaction so as to handle the complex characteristic of trust. Fur-thermore, risk factor is deployed into NatureTrust to represent and reason with the dynamic characteristic of trust. Both risk and trust factors are considered in evaluating the trustworthiness of each peer. Experimental results show that the trust model analyzed here thus stands against malicious act effectively.

Peer priority based data scheduling algorithm in P2P streaming system

In order to solve the problem that the existing data scheduling algorithm cannot make full use of neighbors' bandwidth resources when allocating data request among several senders in the multisender based P2P streaming system,a peer priority based scheduling algorithm is proposed.The algorithm calculates neighbors' priority based on peers' historical service evaluation as well as how many wanted data that the neighbor has.The data request allocated to each neighbor is adjusted dynamically according to the priority when scheduling.Peers with high priority are preferred to allocate more data request.Experiment shows the algorithm can make full use of neighbors' bandwidth resources to transmit data to reduce server pressure effectively and improve system scalability.

Network address translation traversal based on Bernoulli laws of large number in P2P streaming system

P2P streaming application must realize network address translation （NAT） traversal. To handle low success ratio of the existing NAT traversal algorithm, UPnP-STUN （UPUN） and port-mapping sample estimation （PMSE） algorithm are recommended in this paper. UPUN is the combination of UPnP and STUN, and PMSE utilizes port mapping samples added by symmetric NAT for different sessions to estimate regularity of port mapping of symmetric NAT, which takes advantage of the Bernoulli law of large numbers. Besides, for the situation that both peers are behind NAT, and to handle heavy relay server load when many inner peers want to communicate with each other, a peer auxiliary-relay （PAR） algorithm is presented. PAR lets outer peers with sufficient bandwidth act as relay servers to alleviate pressure of real server, which could avoid NAT traversal failure caused by single point failure of relay server. Finally, experiments show that the proposed algorithms could improve the success ratio significantly for NAT traversal in P2P streaming application as well as improve P2P streaming application applicability.