The Security Manager

You can install one with

java -Djava.security.manager application

or in the code with

System.setSecurityManager(new RMISecurityManager());

this last is a much better idea for your RMI code.

In Java there are three policy files that are used.
1. Global policy file. (...jre/lib/security/java.policy)
2. User-specific policy file (HOME/.java.policy)
3. Application-specific set with
```
java -Djava.security.policy="java.policy"
```
The general format is
```
grant [signedBy Name] [codebase URL] {...};
```
where Name and URL can be anything.
The program policytool provides a gui for editing this file.