This paper discusses vulnerabilities of mobile agent based information systems and calls for an increased level of security awareness, which can be achieved by employing self-reliant security features. The paper describes an IS realised as a multi-agent architecture. For a secure channel to exist within the IS, the use of indicator digests reduces the risk of exposing sensitive information to malicious objects. These solutions add to the underlying layer of security offered by the execution environment and work as plug-ins. This enables them to seamlessly integrate with the system they are protecting and to be transparent to the application user.