1. Describe three features that make Java a better programming language than C to write secure programs.
2. Assume that your system is using JDK 1.2. Show the rules (similar to those in Figure 9-40) you will use to allow an applet from www.appletsRus.com to run on your ma- chine. This applet may download additional files from www.appletsRus.com, read/write files in /usr/tmp/, and also read files from /usr/me/appletdir.
3. How are applets different from applications? How does this difference relate to secu- rity?
4. Write a pair of programs, in C or as shell scripts, to send and receive a message by a covert channel on a UNIX system. (Hint: A permission bit can be seen even when a file is otherwise inaccessible, and thesleep command or system call is guaranteed to delay for a fixed time, set by its argument.) Measure the data rate on an idle system. Then create an artificially heavy load by starting up numerous different background processes and measure the data rate again.