基于MASIF的Mobile Agent互操作性的研究与实现

由于当前的诸多Mobile Agent商业系统之间相互协调工作不理想,致使解决Mobile Agent系统之间的互操作性成为研究Mobile Agent技术在实际应用领域中需要解决的首要问题之一。这里的研究以MASIF（Mobile Agent System Interoperability Facilities）规范为蓝本,参考了这一领域中当前的研究成果,对互操作性进行了深入的研究和具体的初步实现,使互操作性标准的价值在实际应用中得到体现。     

Evaluating the security of mobile agent platforms

Mobility of software agents requires additional security measures. While the theoretical aspects of mobile agent security have been widely studied, there are few studies about the security levels of current agent platforms. In this paper, test cases are proposed to assess agent platform security. These tests focus on malicious agents trying to attack other agents or the agency. Currently, they have been carried out for two agent platforms: JADE and SeMoA. These tests show which of the known theoretical security problems are relevant in practice. Furthermore, they reveal how these problems are addressed by the respective platform and what security flaws are present.     

Securing dynamic itineraries for mobile agent applications

In this paper we present a novel mechanism for the protection of dynamic itineraries for mobile agent applications. Itineraries that are decided as the agent goes are essential in complex applications based on mobile agents, but no approach has been presented until now to protect them. We have conceived a cryptographic scheme for shielding dynamic itineraries from tampering, impersonation and disclosure. By using trust strategically, our scheme provides a balanced trade-off between flexibility and security. Our protection scheme has been thought always bearing in mind a feasible implementation, and thus facilitates the development of applications that make use of it. An example application based on a real healthcare scenario is also presented to show its operation.     

Full mobile agent interoperability in an IEEE-FIPA context

The existence of heterogeneous mobile agent systems hinders the interoperability of mobile agents. Several solutions exist, but they are limited in some aspects. This article proposes a full interoperability solution, in the context of the IEEE-FIPA agent standards, composed of three parts. The first part is a simple language-independent agent interface that enables agents to visit locations with different types of middlewares. The second part is a set of design models for the middlewares to support agents developed for different programming languages and architectures. And the third part is a method based on agents with multiple codes and a common agent data encoding mechanism to enable interoperability between middlewares that do not support the same programming languages. Furthermore two agent interoperability implementations, and its corresponding performance comparison, carried out over the JADE and AgentScape agent middlewares are presented.     

一个移动Agent安全旅行协议

本文提出了一种保护移动Agent不受Agent平台攻击的旅行协议。该协议基于Agent旅行的历史记录,在一定的条件下允许Agent所有者检测对Agent代码、状态和执行流的非法篡改。这个协议具有很高的安全性能,能够检测旅行途中的Agent平台对Agent数据的篡改,能够防止重播攻击。     

基于Java移动代理系统的恶意代理问题解决方案

移动代理是一种新的分布式计算模式,安全是其必须解决的问题。针对基于Java移动代理系统的恶意代理问题,尝试提出一种解决方案。该方案主要包括两个方面内容：利用Java2安全机制保护主机资源;采用一种基于证书的移动代理迁移协议,拒绝不合法代理迁移至主机的要求。该方案可以防止移动代理重放攻击。     

一种基于移动Agent的分布式入侵检测系统模型MABDIDS

分析了当前的入侵检测技术的发展及存在的主要缺陷,介绍了移动Agent的概念及其优点,提出了一种新的基于移动Agent的分布式入侵检测模型MABDIDS。MABDIDS利用移动Agent的优点,设计了针对主机和网络两种环境而分别具有不同运行机制的两种检测主体,通过将多个监控节点组织成层次结构来协同实现分布式入侵检测,解决了当前分布式入侵检测系统中存在的主要问题。     

Implementing distributed control system for intelligent mobile robot

The control system of a mobile robot has a number of issues to deal with in real time, including motion control, mapping, localization, path planning, and sensor processing. Intelligent reasoning, task-oriented behaviors, human–robot interfaces, and communications add more tasks to be solved. This naturally leads to a complex hierarchical control system where various tasks have to be processed concurrently. Many low-level tasks can be handled by a robots onboard (host) computer. However, other tasks, such as speech recognition or vision processing, are too computationally intensive for one computer to process. In this case, it is better to consider a distributed design for the control system in networked environments. In order to achieve maximum use of the distributed environment, it is important to design and implement the distributed system and its communication mechanisms in an effective and flexible way. This article describes our approach to designing and implementing a distributed control system for an intelligent mobile robot. We present our implementation of such a distributed control system for a prototype mobile robot. We focus our discussion on the system architecture, distributed communication mechanisms, and distributed robot control.This work was presented, in part, at the 8th International Symposium on Artificial Life and Robotics, Oita, Japan, January 24–26, 2003     

移动Agent系统Ajanta的分析与研究

文章详细地分析了Ajanta系统的运行环境、体系结构、安全性与实现中的一些关键技术,并对该系统中存在的不足与可改进的方案进行了讨论。     

Transparent migration of Java-based mobile agents: Capturing and re-establishing the state of Java programs

In this paper we describe a way to save and restore the state of a running Java program. We achieve this on the language level, without modifying the Java virtual machine, by instrumenting the programmer's original code with a preprocessor. The automatically inserted code saves the runtime information when the program requests state saving and re-establishes the program's runtime state on restart. The current preprocessor prototype is used in a mobile agent scenario to offer transparent agent migration for Java-based mobile agents, but could generally be used to save and re-establish the execution state of any Java program.     

Promoting the development of secure mobile agent applications

In this paper, we present a software architecture and a development environment for the implementation of applications based on secure mobile agents. Recent breakthroughs in mobile agent security have unblocked this technology, but there is still one important issue to overcome: the complexity of programming applications using these security solutions. Our proposal aims to facilitate and speed up the process of implementing cryptographic protocols, and to allow the reuse of these protocols for the development of secure mobile agents. As a result, the proposed architecture and development environment promote the use of mobile agent technology for the implementation of secure distributed applications.     

移动Agent在分布式异构数据库中的应用研究

移动Agent技术是新型的分布计算技术，它及其应用是目前国内外研究和开发的热点。基于CORBA(公共对象请求代理体系结构)和移动Agent，提出了一个解决多媒体异构数据库搜索的体系框架，它可以很好地解决数据传输瓶颈问题。这一框架的性能和可靠性比传统的客户／服务器方法有明显的提高。     

GMAC: An overlay multicast network for mobile agent platforms

The lack of proper support for multicast services in the Internet has hindered the widespread use of applications that rely on group communication services such as mobile software agents. Although they do not require high bandwidth or heavy traffic, these types of applications need to cooperate in a scalable, fair and decentralized way. This paper presents GMAC, an overlay network that implements all multicast related functionality–including membership management and packet forwarding–in the end systems. GMAC introduces a new approach for providing multicast services for mobile agent platforms in a decentralized way, where group members cooperate in a fair way, minimize the protocol overhead, thus achieving great scalability. Simulations comparing GMAC with other approaches, in aspects such as end-to-end group propagation delay, group latency, group bandwidth, protocol overhead, resource utilization and failure recovery, show that GMAC is a scalable and robust solution to provide multicast services in a decentralized way to mobile software agent platforms with requirements similar to MoviLog.     

Autonomous mobile agent routing for efficient server resource allocation

Mobile agents are becoming increasingly important in the highly distributed applications frameworks seen today. Their routing/dispatching from node to node is a very important issue as we need to safeguard application efficiency, achieve better load balancing and resource utilization throughout the underlying network. Selecting the best target server for dispatching a mobile agent is, therefore, a multi-faceted problem that needs to be carefully tackled. In this paper we propose distributed, adaptive routing schemes (next node selection) for mobile agents. The proposed schemes overcome risks like load oscillations, i.e., agents simultaneously abandoning a congested node in search for other, less saturated node. We try to induce different routing decisions taken by agents to achieve load balancing and better utilization of network resources. We consider five different algorithms and evaluate them through simulations. Our findings are quite promising both from the user/application and the network/infrastructure perspective.     

移动Agent互操作性研究

1.引言 Agent的研究起源于人工智能领域,是指模拟人类行为和关系、具有一定智能并能够自主运行和提供相应服务的程序。随着网络技术的发展,可以让Agent在网络中移动并执行,完成某些功能,这就是移动A-gent的思想。移动Agent由于具有任务异步执行、减轻网络负载、健壮性、并行处理、智能路由等特性,自90年代初期以来,对许多领域产生了非常重大的影响。国外一些主要的厂商分别推出Agent系统,然而由于它们采用的技术及设计框架的差异,使得它们难于很好地协调工作。正是在这种背景下,OMG组织制定了MAF(Mobile Agent Facility)规范,随后改为MASIF(Mobile Agent System Interoperability Facili-ty),并于98年三月正式推出,它为解决不同厂商间Agent系统的互操作性提出了一些基本建议。     

A mobile agent platform for distributed network and systems management

The mobile agent (MA) technology has been proposed for the management of networks and distributed systems as an answer to the scalability problems of the centralized paradigm. Management tasks may be assigned to an agent, which delegates and executes management logic in a distributed and autonomous fashion. MA-based management has been a subject of intense research in the past few years, reflected on the proliferation of MA platforms (MAPs) expressly oriented to distributed management. However, most of these platforms impose considerable burden on network and system resources and also lack of essential functionality, such as security mechanisms, fault tolerance, strategies for building network-aware MA itineraries and support for user-friendly customization of MA-based management tasks. In this paper, we discuss the design considerations and implementation details of a complete MAP research prototype that sufficiently addresses all the aforementioned issues. Our MAP has been implemented in Java and optimized for network and systems management applications. The paper also presents the evaluation results of our prototype in real and simulated networking environments.     

Providing early resource allocation during emergencies: The mobile triage tag

Quick response is critical during an emergency situation. This paper describes a system based on mobile electronic triage tags that makes victim information available at the base of operations as soon as possible, thus allowing an early medical resource allocation and immediate action. The cornerstone of the system is mobile agent technology, which allows information to be transported asynchronously and reliably from terminal to terminal and not requiring any network infrastructure at all. This novel approach is ready to be used in the worst case scenario, where only small handheld devices carried by the emergency personnel are available, but also integrates well when synchronous connections are possible, for instance when a mesh network can be created. The system has been successfully implemented, showing the feasibility of the proposal. By using this low-budget system, the number of casualties during the triage stage of an emergency is expected to drop off.     

Protecting mobile agents from external replay attacks

This paper presents a protocol for the protection of mobile agents against external replay attacks. This kind of attacks are performed by malicious platforms when dispatching an agent multiple times to a remote host, thus making it reexecute part of its itinerary. Current proposals aiming to address this problem are based on storing agent identifiers, or trip markers, inside agent platforms, so that future reexecutions can be detected and prevented. The problem of these solutions is that they do not allow the agent to perform legal migrations to the same platform several times. The aim of this paper is to address these issues by presenting a novel solution based on authorisation entities, which allow the agent to be reexecuted on the same platform a number of times determined at runtime. The proposed protocol is secure under the assumption that authorisation entities are trusted.