SECURITY PLAYS AN IMPORTANT ROLE in distributed systems. All parts of a Jini djinn, which consists of clients , services, and lookup services, can be subjected to attack by hostile agents . You could trust everyone, but the large number of attacks that are made on all sorts of systems by both skilled and unskilled people doesn't make this a reasonable approach. The Jini security model is based on the JDK 1.2 security system, and all components of a Jini system use the JDK 1.2 security mechanisms. This can be tricky to set up, and it is looked at in detail in this chapter.