The recent development in the mobile technology (mobile phones, middleware, wireless networks, etc.) created a need for new methods of protecting the code transmitted through the network. The oldest and the simplest mechanisms concentrate more on integrity of the code itself and on the detection of unauthorized manipulation. The newer solutions not only secure the compiled program, but also the data, that can be gathered during its “journey,” and even the execution state. Some other approaches are based on prevention rather than detection. In this chapter we present a new idea of securing mobile agents. The proposed method protects all components of an agent: the code, the data, and the execution state. The proposal is based on a zero-knowledge proof system and a secure secret sharing scheme, two powerful cryptographic primitives. Next, the chapter includes security analysis of the new method and its comparison to other currently more widespread solutions. Finally, we propose a new direction of securing mobile agents by straightening the methods of protecting integrity of the mobile code with risk analysis and a reputation system that helps avoiding a high-risk behavior.Request access from your librarian to read this chapter's full text.
Chen Su, Tiejian Luo, Wei Liu, Jinliang Song · 5 authors
In an e-Science environment, large-scale distributed resources in autonomous domains are aggregated by unified collaborative platforms to support scientific research across organizational boundaries. In order to enhance the scalability of access management, an integrated approach for decentralizing the task from resource owners to administrators on the platform is needed. We propose an extensible access management framework to meet this requirement by supporting an administrative delegation policy. This feature allows administrators on the platform to make new policies based on the original policies made by resources owners. An access protocol that merges SAML and XACML is also included in the framework. It defines how distributed parties operate with each other to make decentralized authorization decisions.
SSO (single sign on) provides e-commerce users with easy access to applications and network resources, using a single, secure login identity. Web services (WS) based on SSO provide the potential to achieve interoperability of distributed electronic commerce (e-commerce) application integration among autonomous organizations, regardless of platforms, operating systems or languages. The most important challenge about the WS based on security SSO is the cost of implementation. After reviewing the paradigm of developing WS security standards and challenges, this paper presented a security model of JSON (JavaScript object notation) based on SSO architecture for e-commerce enterprise. The decentralized SSO security architecture is presented which is easy to integrate legacy system and new developed system.
Recently, there have been considerable efforts towards the convergence between P2P and Grid computing in order to reach a solution that takes the best of both worlds by exploiting the advantages that each offers. Augmenting the peer-to-peer model to the services of the Grid promises to eliminate bottlenecks and ensure greater scalability, availability, and fault-tolerance. The Grid Information Service (GIS) directly influences quality of service for grid platforms. Most of the proposed solutions for decentralizing the GIS are based on completely flat overlays. The main contributions for this paper are: the investigation of a novel resource discovery framework for Grid implementations based on a hierarchy of structured peer-to-peer overlay networks, and introducing a discovery algorithm utilizing the proposed framework. Validation of the framework-s performance is done via simulation. Experimental results show that the proposed organization has the advantage of being scalable while providing fault-isolation, effective bandwidth utilization, and hierarchical access control. In addition, it will lead to a reliable, guaranteed sub-linear search which returns results within a bounded interval of time and with a smaller amount of generated traffic within each domain.
A network community is a special sub-network that contains a group of nodes sharing similar linked patterns. A distributed network community mining problem (D-NCMP) is concerned with finding all such communities from a distributed network. A variety of applications in WWW and ad-hoc networks such as P2P and sensor networks can be formulated into DNCMPs, in which both resources and controls are distributed and/or decentralized. The problem is difficult for some existing methods to deal with because of the fact that their required global topological representations of distributed networks are hard to obtain. In this paper, we present an autonomy oriented computing (AOC) approach [15], in which the nodes and links of a distributed network are distributed among a group of autonomous agents that collectively find global communities hidden in the network. In doing so, the agents maintain only their respective local views and update them through a proposed self-organization process. The effectiveness of the AOC based approach has been validated using network examples.
Nathaniel E. Baughman, Marc Liberatore, Brian Neil Levine
We explore exploits possible for cheating in real-time, multiplayer games for both client-server and serverless architectures. We offer the first formalization of cheating in online games and propose an initial set of strong solutions. We propose a protocol that has provable anti-cheating guarantees, is provably safe and live, but suffers a performance penalty. We then develop an extended version of this protocol, called asynchronous synchronization, which avoids the penalty, is serverless, offers provable anti-cheating guarantees, is robust in the presence of packet loss, and provides for significantly increased communication performance. This technique is applicable to common game features as well as clustering and cell-based techniques for massively multiplayer games. Specifically, we provide a zero-knowledge proof protocol so that players are within a specific range of each other, and otherwise have no notion of their distance. Our performance claims are backed by analysis using a simulation based on real game traces
This paper describes an idea of securing mobile agents. The presented method protects all the code, the data and the execution state. The proposal is based on a zero-knowledge proof system and a secure secret sharing scheme. The paper also gives security analysis of the new method.
As data generation becomes increasingly inherently distributed, either due to usergenerated (multimedia) content or because of application-specific needs (sensor networks, data streams, etc.), traditional centralized architectures fail to address the new challenges of contemporary data management.A promising solution for the design and deployment of global-scale applications is the exploitation of the peer-to-peer (P2P) paradigm.P2P has emerged as a powerful model for organizing and searching large data repositories distributed over autonomous independent sources.The main topic and contribution of this thesis is the unsupervised organization of content into Semantic Overlay Networks (SONs), in a decentralized and distributed manner, and subsequently a variety of techniques for efficient searching and query processing in unstructured P2P systems.SONs have been proposed in the relevant research literature, as a way to organize peers into thematic groups, thereby enabling query routing to specific peer groups in a deliberate way, instead of blind forwarding.In particular, this work focuses on unstructured P2P networks that preserve peer autonomy.A novel protocol for unsupervised, distributed and decentralized SON construction is proposed, named DESENT [35,38], which employs distributed clustering of peer contents, respecting the requirements imposed by the distributed nature of the environment [138].Exploiting the generated SONs, we propose efficient routing strategies for answering similarity search queries [37,39].The approach is applied and tested in a distributed IR setting, aiming to address some of the limitations of P2P IR/web search.Towards this goal, a distributed dimensionality reduction algorithm is proposed [96], in order to reduce the high-dimensional feature space and improve clustering quality.Assuming a super-peer architecture we propose an approach called SIMPEER [43] that efficiently supports similarity search over data distributed over a large set of peers.We show how range queries and nearest neighbor queries can be processed.We also explore how to support non-traditional queries (such as top-k [141] and skylines [139]) that involve ranking.Furthermore, by relaxing the restriction of completely unsupervised environment and assuming a semi-supervised context, a novel technique for P2P summary caching of hierarchical information is presented, exploiting either predefined taxonomies [104] or XML schema information [36,40], which is applied in mobile P2P context-aware environments to improve query routing [45,44].6.4 Measurements from using different number of querying peers, given as the fraction of peers in the network. . . . . . . . . . . . . . . . .6.5 Measurements from using different skew (represented by increasing values of a) in the query distributions. . . . . . . . . . . . . . . . . .6.6 Measurements for different network
The recent developments in the mobile technology (mobile phones, middleware) created a need for new methods of protecting the code transmitted through the network. The oldest and the simplest mechanisms concentrate more on integrity of the code itself and on the detection of unauthorized manipulation. The newer solutions not only secure the compiled program, but also the data, that can be gathered during its journey and even the execution state. Some other approaches base on prevention rather than detection. This paper describes a new idea of securing mobile agents. The presented method protects all: the code, the data and the execution state. The proposal is based on a zero-knowledge proof system and a secure secret sharing scheme, two powerful cryptographic primitives. The paper also includes security analysis of the new method and comparison to currently most widespread solutions.
Networked systems are continuously growing in scale and complexity. The technical and policy engineering challenges introduced by such a fast growth are currently addressed locally, with limited understanding of their impact on the whole. Such approaches are becoming impractical and insufficient. Next-generation networks need to address these issues by deploying adaptive and self-managing protocols and mechanisms to relax the persistent need for human-driven management. However, achieving these objectives requires conceptual, physical, and logistical modifications to existing systems and protocols. To this end, the traditional top-down approach to network and application design needs to be supplemented by understanding the bottom-up nature of evolving real-world networks.A critical issue that is significantly impacting computer networks and applications is the absence of an in-depth understanding and lack of control over the structural properties, i.e., topology, of large networks. Network topologies define the link relationships between the nodes in the network, and have a direct impact on the performance, resilience, and security of distributed applications. Large scale networks such as the Internet are the result of a time evolving process in which nodes and links between nodes are added, removed, and reconfigured dynamically. This dynamic process takes place in a decentralized manner during which nodes make local adaptations and reconfiguration decisions that optimize local properties. As a result, these local perturbations yield an emergent network that is often unstructured and complex, and have implications at the application-level, particularly impacting routing, search, robustness, and clustering. Understanding the structures emerging out of these adaptations is a complex problem part of the science and study of complexity theory and complex adaptive systems. Tackling this complex problem requires first, identifying canonical metrics to quantify the network topology and second, analyzing the impact of local perturbations of these metrics on the resulting network topology.This thesis identifies three local metrics, transitivity, assortativity, and entropy, and analyzes the impact of their perturbation on the applications of routing, search, robustness, and clustering. The local metric of network entropy is identified as a useful information theoretic measure of homogeneity of a network neighborhood degree. The metric is further used to derive a novel mechanism of clustering detection of the network topology. The overall objective of this thesis is to investigate metrics and mechanisms to better understand the evolution of the network topology and its impact on application-level functionality. The approach is based on concepts of emergence, self-organization and graph theory, and has three key aspects: (1) the identification of canonical local and global graph metrics; (2) the quantitative analysis of the impact of local perturbations on global properties; and (3) the application of the local to global mapping on the problems of routing, search, robustness, and clustering. Adaptations are performed in a decentralized manner in which local nodes use local information to add, remove, or rewire an edge to evolve the topology. Simulations based on annealing optimization are conducted to empirically determine the optimal bounds of the network structures for the selected metrics on selected networks. Further experiments on two modeled networks, random and power-law degree distributed, and two real-world networks, the Gnutella and Canadian Autonomous System networks, show that the impact of optimizing networks with fixed degree distribution on local metrics yield networks with routing, search, robustness, and clustering that are tightly dependent on the network's degree distribution. A key outcome of this thesis is the identification of network entropy minimization as a useful local rewiring strategy to decrease average path length and search cost, while homogenizing the size of network clusters and having a low impact on robustness when applied to power-law degree distributed networks that prevail in real-world networks.
While the pervasiveness of wireless technology has provided a major impetus to mobile services,challenges the mobility of mobile services much.The characteristics of personal environments:heterogeneity,short distance between devices,and group mobility,are analyzed,and a decentralized directory storage method is proposed based on them for the autonomous organization of devices.It provides proper group mobility support and saves bandwidth,so that,improves the stability of system in personal environments.
Fundamental challenges in designing environments with media-rich ambient services involves not only the development of appropriate sensing technologies, but as importantly, the implementation of a distributed media processing system which can process, integrate, and leverage the sensed data in real time to provide the various services. In recent years, a great deal of progress has been made in media service workflow processing systems. In most existing solutions, however, the workflow nodes, which operate on the data, are selected out of a centrally assigned candidate pool. These candidate organizations cause either extensive resource provisioning or poor-quality operator mapping between logical workflow nodes and the available physical resources nodes. Consequently, instantiating a media processing workflow to the underlying hardware before the workflow execution begins does not lends itself to adaptive and autonomous operation of the workflow, scalable to resources and demand.In this paper, we propose a novel decentralized multimedia workflow processing system, DANS, in which operators defined in workflows are mapped into (distributed) physical nodes through Distributed Hash Table (DHT)-based overlay substrate in a purely decentralized and adaptive manner. The redundancy in the system, in terms of availability of multiple nodes able to perform the same task, enables the system to scale with demand. Furthermore, physical workflow nodes (operator instances) are able to locate and select the next filter or fusion operator instance autonomously, while ensuring the correct execution of the workflow.
A.J. Chakravarti, Gerald Baumgartner, Mario Lauria
The Organic Grid is a biologically inspired and fully decentralized approach to the organization of computation that is based on the autonomous scheduling of strongly mobile agents on a peer-to-peer network. Through the careful design of agent behavior, the emerging organization of the computation can be customized for different classes of applications. In this paper, we report on our experience in adapting the general framework to run two representative applications on our Organic Grid prototype: the National Center for Biotechnology Information (NCBI) basic local alignment search tool (BLAST) code for sequence alignment, and the Cannon's algorithm for matrix multiplication. The first is an example of independent task application, a type of application commonly used for grid scheduling research because of its easily decomposable nature and absence of intra-node communication. The second is a popular block algorithm for parallel matrix multiplication, and represents a challenging application for grid platforms because of its highly structured and synchronous communication pattern. Agent behavior completely determines the way computation is organized on the Organic Grid. We intentionally chose two applications at opposite ends of the distributed computing spectrum having very different requirements in terms of communication topology, resource use, and response to faults. We detail the design of the agent behavior and show how the different requirements can be satisfied. By encapsulating application code and scheduling functionality into mobile agents, we decouple both computation and scheduling from the underlying grid infrastructure. In the resulting system, every node can inject a computation onto the grid; the computation naturally organizes itself around available resources.
Omar Khadeer Hussain, Elizabeth Chang, Farookh Khadeer Hussain, Tharam S. Dillon
Risk is present in almost every activity. Alternately speaking, almost every activity may have some undesired outcomes which the person doing the activity hopes that they do not occur when it undertakes that particular activity. The quantification of those undesired outcomes can be termed as Risk. Risk is associated with Trust, Security and Privacy. Risk is also associated with transactions, businesses, information systems, environments, networks, partnerships, etc. Generally speaking, Risk signifies the likelihood of financial loss, human casualties, business destruction and environmental damages. It is important to define Risk according to the context of the transaction in order to understand and analyse it better. In the literature Risk has been defined and discussed in areas such as security, health, finance, environment and social life, but there is no systematic study of Risk in decentralized communications, which involves e-business, computer networks and service oriented environments. Hence in this paper, a particular attention is given to define and analyse Risk in the area of Peer-to-Peer business communications, where Risk is every individual and organization?s concern. Also in this paper we develop a risk indicator scale and develop a methodology by which the Riskiness of the peer can be rated according to its behaviour in an interaction. Risk indicator gives an early warning to the party involved and helps avoid disasters.
Xu Wang, Yang Ji, Xiaosheng Tang, Yinong Li · 5 authors
Our objective is to build a distributed terminal system to provide smart, context-aware, rich-experienced applications upon personal environment networking technologies, such as WLAN, IEEE 802.15.3 series, ZigBee, Bluetooth, etc. For the proliferation of smart devices with autonomous applications, the users can get much more service experiences than before. While smart devices facilitate human operation, the coordination of devices through networks may provide applications proactively by gathering much more service context, which indicates the emergence of the pervasive computing age. Hence, we proposed the distributed terminal system for the cooperating of smart devices. In this paper, we analyzed the organization architecture of universal service terminal (UST), the distributed terminal system proposed by us before. In UST project, we have abstracted and encapsulated the capabilities of devices as servers for remote invocation by applications, moreover, the framework functionalities have been introduced for the organization of the distributed system. Though the architecture of UST has been validated feasible in a demonstration, the centralized control mechanisms in the heterogeneous environment are inefficient and unreliable. Thus, we propose an evolved scheme by introducing decentralized mechanisms in this paper. The devices around the user are organized in an overlay peer-to-peer network, and some powerful nodes of them provide the decentralized mechanisms for resource management, service discovery, etc
A.J. Chakravarti, Gerald Baumgartner, Mario Lauria
We propose a biologically inspired and fully-decentralized approach to the organization of computation that is based on the autonomous scheduling of strongly mobile agents on a peer-to-peer network. Our approach achieves the following design objectives: near-zero knowledge of network topology, zero knowledge of system status, autonomous scheduling, distributed computation, lack of specialized nodes. Every node is equally responsible for scheduling and computation, both of which are performed with practically no information about the system. We believe that this model is ideally suited for large-scale unstructured grids such as desktop grids. This model avoids the extensive system knowledge requirements of traditional grid scheduling approaches. Contrary to the popular master/worker organization of current desktop grids, our approach does not rely on specialized super-servers or on application-specific clients. By encapsulating computation and scheduling behavior into mobile agents, we decouple both application code and scheduling functionality from the underlying infrastructure. The resulting system is one where every node can start a large grid job, and where the computation naturally organizes itself around available resources. Through the careful design of agent behavior, the resulting global organization of the computation can be customized for different classes of applications. In a previous paper, we described a proof-of-concept prototype for an independent task application. In this paper, we generalize the scheduling framework and demonstrate that our approach is applicable to a computation with a highly synchronous communication pattern, namely Cannon's matrix multiplication.
By applying the secret sharing system and the zero knowledge proof protocol,this paper presents a new time constraint delegation of the decryption scheme based on trust agent platforms,which solves the problem that the accessed peer cannot offer instant data when it is offline.This scheme carries out encryption and decryption by using ElGamal cryptography.It defines the delegating-agents protocol,the produce of the delegation-key protocol and the decryption protocol,thus implementing the cheat-resisted and quorum controlled time constraint delegation of decryption.And the new scheme is supplemented to settle the problems of the key being renewed dynamically,the agent being added or deleted and the agent's information being maintained.Compared with the previous time constraint delegation of the decryption scheme,it improves security,flexibility and efficiency.
Abstract. There is a broad literature on distributed card games over communications networks, collectively known as mental poker. Likein any distributed protocol, avoiding the need for a Trusted Third Party (TTP) in mental poker is highly desirable, because really trusted TTPs are not always available and seldom free. This paper deals with the player dropout problem in mental poker without a TTP. A solution based on zero-knowledge proofs is proposed. While staying TTP-free, our proposal allows the game to continue after player dropout.
A.J. Chakravarti, Gerald Baumgartner, Mario Lauria
Desktop grids have recently been used to perform some of the largest computations in the world and have the potential to grow by several more orders of magnitude. However, current approaches to utilizing desktop resources require either centralized servers or extensive knowledge of the underlying system, limiting their scalability. We propose a biologically inspired and fully-decentralized approach to the organization of computation that is based on the autonomous scheduling of strongly mobile agents on a peer-to-peer network. In a radical departure from current models, we envision large-scale desktop grids in which agents autonomously organize themselves so as to maximize resource utilization. By encapsulating computation and behavior into agents, the organization of the computation can be customized for different classes of applications. At the same time, the design of the underlying infrastructure is greatly simplified, resulting in a system that naturally lends itself to a true peer-to-peer implementation where each node can be at the same time provider and user of the computing utility infrastructure. We demonstrate this concept with a reduced-scale proof-of-concept implementation that executes a data-intensive independent-task application on a set of heterogeneous, geographically distributed machines. We present a detailed exploration of the design space of our system and a performance evaluation of our implementation using metrics appropriate for assessing self-organizing desktop grids.
We consider the problem of deploying and managing federated services that run on federated systems spanning multiple collaborative organizations. In particular, we present a peer-to-peer framework targeted to the construction of self-managing services that automatically adjust the number of service components and their placements in response to changes in the system or client loads. Our framework is completely decentralized, depending only on a modest amount of loosely synchronized global state. More specifically, our framework is comprised of a set of per-node monitoring agents and per-service-component management agents that periodically exchange information about the state of the system and of the service with each other using a gossiping protocol. Each management agent then periodically searches for configurations that are better than the current one according to an application model and explicit performance and availability targets. On finding a better configuration, an agent will enact the new configuration after a random delay to avoid possible collisions. We evaluate our framework by studying a prototype UDDI service. We show that while agents act autonomously, the service rapidly reaches a stable and appropriate configuration in response to system dynamics.