Protocols for Malicious Host Revocation

A highly secure mobile agent system is very important for a mobile computing environment. The security issues in mobile agent system comprise protecting mobile hosts from malicious agents, protecting agents from other malicious agents, protecting hosts from other malicious hosts and protecting agents from malicious hosts. Using traditional security mechanisms the first three security problems can be solved. Apart from using trusted hardware, very few approaches exist to protect mobile code from malicious hosts. Some of the approaches to solve this problem are the use of trusted computing, computing with encrypted function, steganography, cryptographic traces, Seal Calculas, etc. This paper focuses on the simulation of some of these existing techniques in the designed mobile language. Some new approaches to solve malicious network problem and agent tampering problem are developed using public key encryption system and steganographic concepts. The approaches are based on encrypting and hiding the partial solutions of the mobile agents. The partial results are stored and the address of the storage is destroyed as the agent moves from one host to another host. This allows only the originator to make use of the partial results. Through these approaches some of the existing problems are solved.

Mobile agents' paradigm is increasingly being used on the global Internet, distributed systems and ambient intelligence environment. Indeed, they can provide many advantages to the development of dynamic applications. More recently, mobile agent paradigm is of the best prevalent alternatives bringing most of suitable characteristics of pervasive environments, where people are surrounded by intelligent interfaces merged in daily life objects. Yet, the success of dynamic environment based mobile agents and multi agent systems will depend on how secure it can be made. Certainly, their use poses many security threats, because they are exposed to different malicious hosts' and nodes attacks. The aim of this paper is to propose CAPMA, Clone agent to protect mobile agents. The approach is based on adaptability concept and a clone agent, which is a prototype of the mobile agent with no critical code and sensitive data. The idea minimizes damages on the mobile agent.

Mobile agents are software entities consisting of code and data that can migrate autonomously from host to host executing their code. Despite its benefits, security issues strongly restrict the use of code mobility. The protection of mobile agents against the attacks of malicious hosts is considered the most difficult security problem to solve in mobile agent systems.The approach that is presented here detects manipulation attacks performed during the agent’s execution. Software watermarking techniques are used in order to embed a mark into the agent. The agent’s execution creates marked results. When the agent returns to the origin host, these results are examined in order to find the embedded mark. If the mark has changed, this means that the executing host has modified the agent. Colluding hosts can also be identified by using codes with the identifiable parent property (IPP) as marks, i.e. mobile agent fingerprinting.KeywordsMobile AgentWatermark SchemeOrigin HostMalicious BehaviorCollusion AttackThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Mobile agent-based computing is an attractive model for distributed computation environment. A mobile agent has the unique ability to transfer from one host to another in the network. In multi-hop mobile agent system, the agent brings the produced offer from various remote hosts to its owner only after completing the visit to many remote hosts. Carrying the offer gathered from the preceding hosts to the succeeding hosts requires much security mechanisms to protect the offer from the malicious hosts, and also the owner has to wait for the arrival of offer until the mobile agent finishes its travel. To overcome this, an alternative model has been developed called matrix hop mobile agent (MHMA) system in which the mobile agent sends the offer collected from the host to the owner before it migrates to the next host. This research work proposes a new fault tolerant mechanism for MHMA to identify the malicious host and to protect the agent from various attacks, including colluded attack. In this proposed model, the owner calculates the expected waiting time for the arrival of offer from each remote host, using the transmission cost. If the offer does not reach the owner within the waiting time, the owner identifies the agent’s failure and retransmits the agent directly to the remote host. The implementation of this model enhances the performance of the MMHA in all kinds of e-service applications.

The flexibility offered by mobile agents is quite noticeable in distributed computing environments. However, the greater flexibility of the mobile agent paradigm compared to the client/server computing paradigm comes at an additional threats since agent systems are prone to failures originating from bad communication, security attacks, agent server crashes, system resources unavailability, network congestion, or even deadlock situations. In such events, mobile agents either get lost or damaged (partially or totally) during execution. In this paper, we propose parallel checkpointing approach based on the use of antecedence graphs for providing fault tolerance in mobile agent systems. During normal computation message transmission, the dependency information among mobile agents is recorded in the form of antecedence graphs by participating mobile agents of mobile agent group. When a checkpointing procedure begins, the initiator concurrently informs relevant mobile agents, which minimizes the identifying time. The proposed scheme utilizes the checkpointed information for fault tolerance which is stored in form of antecedence graphs. In case of failures, using checkpointed information, the antecedence graphs and message logs are regenerated for recovery and then normal operation continued. Moreover, compared with the existing schemes, our algorithm involves the minimum number of mobile agents during the identifying and checkpoiting procedure, which leads to the improvement of the system performance. In addition, the proposed algorithm is a domino-free checkpointing algorithm, which is especially desirable for mobile agent systems. Quantitative analysis and experimental simulation show that our algorithm outperforms other coordinated checkpointing schemes in terms of the identifying time and the number of blocked mobile agents and then can provide a better system performance. The main contribution of the proposed checkpointing scheme is the enhancement of graph-based approach in terms of considerable improvement by reducing message overhead, execution, and recovery times.

Over the last couple of years we have been working on the development of mobile agents systems and their application to the areas of telecommunications and network management. This work has produced positive results: a competitive mobile agent platform was built, the run-time benefits of mobile agents were proved, and our industrial partners have developed practical applications that are being integrated into commercial products. However, despite the positive results, we feel that mobile agent technology is still not ready to enter the path of mainstream software development. In our perspective, one of the main reasons for this situation arises from the traditional approach to mobile agent technology. This approach, based on the familiar concept of the mobile-agent distributed platform as an extension of the operating system, focuses too much on the mobile agents and associated issues (mobility, agent lifecycle, security, coordination, etc.) and provides poor support for the development of applications where mobile agents are just one of several available technologies. Learning from past experience, we are now working on a new approach where the focus is brought back to the applications and mobile agents become just one the tools available to develop distributed systems. This provides a much lighter framework for application-based mobile agent systems. This paper presents the lessons learned from our previous project and discusses the new concept we are developing: application-centric mobile agent systems.

The security problem of mobile agent is important for applications using mobile agent technology. In this paper, we analyzed the security problems of mobile agent system exposed in opening environment and proposed a method to improve the authentication and credentials management in mobile agent environment. In our design, the trusted computing platform is used as the basic platform to running mobile agent systems, and the trusted platform module will used to help the authentication and credentials management. We also gave a model system for building trusted mobile agent system. In this system, the security of mobile agent is improved by using trusted computing platform which is linked with upper layer applications through the trusted software stack. Then, trusted services for mobile agent, including authentication, credential management and key storage, are supported.

Mobile agents can provide many benefits to the development of distributed applications. But the mobile agent system will face some security threat since it will run in an opening network environment. In this paper, we analyzed the security threats in mobile agent system and provided a method to build the trusted connect between entities in mobile agent environment. This method uses the trusted platform module in trusted computing platform as the trusted base. When a mobile agent wants to migrate to another platform, it should use a trusted connect between the source host and the goal host. The agent and agent platform can trust with each other. This method will be helpful to build a trusted computing environment for the mobile agent system.

Detecting and resolving deadlocks in mobile agent systems

Aiming at the security and trust management of mobile agent system in cloud computing environment, based on the simple public key infrastructure (SPKI) trust mechanism, a mobile agent system objective trust peer management model (MAOTM) is proposed to solve the problem of identity authentication, operation authorization and access control in the mobile agent system; On this basis, the Human Trust Mechanism (HTM) is used to study the subjective trust formation, trust propagation and trust evolution law, and the subjective trust dynamic management algorithm (MASTM) is proposed. Based on the interaction experience between the mobile agent and the execution host and the third-party recommendation information to collect the basic trust data, the public trust host selection algorithm is given. The isolated malicious host algorithm and the integrated trust degree calculation algorithm realize the function of selecting the trusted cluster and isolating the malicious host, so as to enhance the security interaction between the mobile agent and the host. The simulations of the proposed algorithms are verified and proved to be feasible and effective.

Mobile agents are autonomous and dynamic entities that can migrate among various nodes in the network. Java`s Jini framework facilitates mobile agent system development, providing hey features for distributed network programming. However, due to the security weakness, Jinil.0 service has a fundamental limitation on developing mobile agent systems which support secure remote communications. In this paper, we describe a Jini2.0-based secure mobile agent system named SecureJMoblet. On the top of Jini2.0, the system provides basic functionalities of a mobile agent system such as creation, transfer and control. In addition, with the SeureJS developed for secure JavaSpace service, SecureJMoblet supports a secure object repository and a reliable communication among mobile agents.

The system of mobile agents described here is like a beehive: agents (like bees) swarm off to do their duties, wandering to different places, and finally returning to their origin. The main insight of this work is how to specifically separate the different functionalities in such a system of mobile agents, and in particular a description of the cooperative processes is given. In fact, modeling the cooperation of agents is at the heart of this proposal. This paper proposes the specification of a mobile system in an object oriented specification language, thus permitting to model a system without binding it to a particular language, an implementation platform or a programming model. The specification is an architectural description of the system, focusing on its components, their functionalities and connectors. It helps making assumptions and hence properties of the system explicit, it will be used as a blueprint for the implementation of a framework which supports mobile agents.

Although the mobile agent paradigm provides great potential advantages ever traditional approaches in distributed computing applications, there are still several issues to be addressed before the technology can be widely accepted. The performance of the communication protocol is one of the critical issues in mobile agent systems. A practical communication protocol for mobile agents must satisfy three basic requirements: location transparency, reliability and efficiency. Although many communication protocols have been proposed for mobile agent systems and most of them are location transparent, these protocols usually compromise some aspects of reliability and efficiency. In this research we develop a communication scheme for efficient location tracking of agents and reliable message delivery in mobile agent systems by using a proxy-based scheme. The location update and message delivery protocols are developed and shown to be reliable even when agents migrate during message delivery. A simulation model is developed to estimate the performance relative to a (nonproxy-based) home-server protocol. Sensitivity analysis is used to reveal the important circumstances (domain/agent dimensions and exogenous demand/movement characteristics) for efficient communication performance.

Mobile agents are a new paradigm for distributed computing that is especially well suited for mobile computing over global wireless networks. This paper describes the approach taken in the ACTS On TheMove project to integrate a mobile agent system into the Mobile Application Support Environment (MASE), a middleware for mobile computing. In this project, an existing mobile agent system was adapted for the requirements of mobile computing. We present the changes that had to be made to the agent system to adapt it to the wireless communication. We also present some of the application areas where a mobile agent system is suitable for mobile communication. We describe an agent based pre-fetcher application where an agent operaes disconnected from the user on the fixed network and prepares web pages for the anticipated next connection of the user using the Quality-of-Service trading functions available in MASE.

A mobile agent is a software program which migrates from a site to another site to perform tasks assigned by a user. For the mobile agent system to support agents in various application areas, the issues regarding reliable agent execution, as well as compatibility between two different agent systems or secure agent migration, have been considered. Some of the proposed schemes are either replicating the agents (Hamidi & Mohammadi, 2005) or check-pointing the agents (Park, Byun, Kim, & Yeom, 2002; Pleisch & Schiper, 2001;) For a single agent environment without considering inter-agent communication, the performance of the replication scheme and the check-pointing scheme is compared in Park et al. (2002) and Silva, Batista, and Silva (2000). In the area of mobile agents, only few works can be found relating to fault tolerance. Most of them refer to special agent systems or cover only some special aspects relating to mobile agents, such as the communication subsystem. Nevertheless, most people working with mobile agents consider fault tolerance to be an important issue (Izatt, Chan, & Brecht, 1999; Shiraishi, Enokido, & Takzawa, 2003). Mobile agents are becoming a major trend for designing distributed systems and applications in the last few years and foreseeable future. It can bring benefits such as reduced network load and overcoming of network latency (Chan, Won, & Lyu, 1993). Nevertheless, security is one of the limiting factors of the development of these systems. The main unsolved security problem lies in the possible existence of malicious hosts that can manipulate the execution and data of agents (Defago, Schiper, & Sergent, 1998). Most distributed applications we see today are deploying the client/server paradigm. There are certain problems with the client/server paradigm, such as the requirement of a high network bandwidth, and continuous user-computer interactivity. In view of the deficiencies of the client/server paradigm, the mobile code paradigm has been developed as an alternative approach for distributed application design. In the client/server paradigm, programs cannot move across different machines and must run on the machines they reside on. The mobile code paradigm, on the other hand, allows programs to be transferred among and executed on different computers. By allowing code to move between hosts, programs can interact on the same computer instead of over the network. Therefore, communication cost can be reduced. Besides, mobile agent (Fischer, Lynch, & Paterson, 1983) programs can be designed to work on behalf of users autonomously. This autonomy allows users to delegate their tasks to the mobile agents, and not to stay continuously in front of the computer terminal. The promises of the mobile code paradigm bring about active research in its realization. Most researchers, however, agree that security concerns are a hurdle (Greenberg, Byington, & Harper, 1998). In this article, we investigate these concerns. First, we review some of the foundation materials of the mobile code paradigm. We elaborate Ghezzi and Vigna’s classification of mobile code paradigms (Ghezzi & Vigna, 1997), which is a collection of the remote evaluation, code on demand, and mobile agent approaches. In the next section, we address the current status of mobile code security. The following section presents the model for fault-tolerant mobile agent. In the next section, security issues of the mobile agent are discussed, and we discuss security modeling and evaluation for the mobile agent in the section after. In the following section, simulation results and influence of the size of agent are discussed. We then conclude the article.