Hartmut Vogler

An approach for mobile agent security and fault tolerance using distributed transactions

Mobile agents are no longer a theoretical issue since different architectures for their realization have been proposed. With the increasing market of electronic commerce it becomes an interesting aspect to use autonomous mobile agents for electronic business transactions. Being involved in money transactions, supplementary security features for mobile agent systems have to be ensured. In this paper we present an architecture for a mobile agent system which guarantees security for the host as well as security for the agent. This architecture additionally offers fault tolerance for the whole agent system at a high level. To handle these issues for mobile agents we use various encryption mechanisms and we apply a novel method for mobile agent systems by using distributed transactions processing based on the OMG Object Transaction Service in our architecture. With this security architecture an agent will be enabled to do money transactions.

Distributed transaction processing as a reliability concept for mobile agents

Mobile agents offer a new possibility for the development of applications in distributed systems and are no longer a theoretical issue since different architectures for their implementations have been proposed. With the increasing market of electronic commerce it becomes an interesting idea to use autonomous mobile agents for electronic business transactions. Being involved in money transactions, supplementary security features for mobile agent systems have to be ensured. We present an architecture for a mobile agent system which offers fault tolerance for the whole agent system at a high level. This architecture additionally guarantees security for the host as well as security for the agent. To handle these issues for mobile agents we use various encryption mechanisms and we apply a novel method for mobile agent systems by using distributed transactions in our architecture. Due to this security architecture an agent will be enabled to carry out money transactions.

Enhancing Mobile Agents with Electronic Commerce Capabilities

The paradigm of mobile agents offers a powerful and flexible opportunity to develop distributed applications on a high-level of abstraction. One of the most interesting tasks for mobile agents is an active search for relevant information in non-local domains on behalf of their users. A mobile agent will be sent out on behalf of an user to various host servers in the Internet and to find information. In the future this information might not be freely accessible, so the agent may have to pay for them. Thus the mobile agent has to be equipped with electronic commerce capabilities. This implies a fault tolerant and secure infrastructure for the mobile agent. In this paper we present a system which offers electronic commerce capabilities for mobile agents. These capabilities a part of an architecture which guarantees different security issues and fault tolerance for mobile agents. Security for the partners involved is handled by encryption methods based on a public key authentication mechanism and by secret key encryption of the communication. To achieve fault tolerance for the agent system, especially for the agent transfer to a new host, we use Distributed Transaction Processing (DTP). This architecture can be used on top of existing mobile agent systems, e.g. as an enhancement of the “GO-Statement”, and offers a high reliability because the implementation is based on standardized components.

Using multiple mobile agents for distributed transactions

Agent systems are well suited for applications requiring great flexibility. We propose a mechanism that uses multiple mobile agents to implement distributed transactions in a wide area network. Of special interest are applications in which resources change over time. By using multiple, mobile and autonomous agents in our model we are able to monitor resources in a distributed system and to react to changes in a very flexible manner. Each agent is responsible for a single resource and corresponds with the Object Transaction Service (OTS) for the coordination of the global transaction. For the management and the control of the agents we propose X-TRA, our extensible trusted agent system which offers a trust service for agent identification and control with exactly once semantics for agent migration, controlled agent termination, grouping of agents, and a bank service.

Protecting competitive negotiation of mobile agents

The paradigm of mobile agents reached its popularity and attraction from typical application scenarios, which are located in the area of electronic commerce. In these common application scenarios, mobile agents get a task from its owner to buy certain goods. To fulfill this task the agent wanders to various merchants and collects information about the different offers. In this paper we present an architecture that allows mobile agents to autonomously and automatically negotiate with vendors about offers. The approach allows evaluating multiple issues of an offer such as price, guarantee or shipping fees, by special scoring functions. The process of negotiation in the area of electronic commerce is competitive. Thus the agent platform must avoid that vendors can spy which tactic and strategy the mobile agents use. To ensure the relevant information for the negotiation mechanisms and functions we use a pair of cooperating agents to achieve a secret splitting.

Scalable Security Mechanisms in Transport Systems for Enhanced Multimedia Services

Data confidentiality is a very important issue for communication in open networks. Secure communication usually will be achieved by encryption mechanisms. For distributed multimedia applications the usage of encryption in real-time can cause a performance problem due to the time complexity of the cryptographic algorithms. In these cases partial encryption is a solution to satisfy real-time demands.

STDL as a High-Level Interoperability Concept for Distributed Transaction Processing Systems

The Structured Transaction Definition Language (STDL) is a language-based programming interface to transactional protocols and runtime systems. STDL isolates within the language transaction processing features, allowing an implementation to hide underlying communications mechanisms, like TxRPC and CORBA/OTS, from the programmer. Because of its design centre in distributed processing, STDL already includes many features of object-oriented systems. Completing the transformation to an object-oriented language provides a migration path from procedure-oriented TP to object-oriented TP and simplifies the substitution of object-oriented communication managers.