However, they are not the total answer. Encryption should be wisely used to protect sensitive information from 'unauthorized eyes'. It is no secret that foreign competitors of large U S corporations gainfully employ former Eastern Block intelligence agents. You see, it is more cost effective to steal the secrets of your competition than it is to spend millions of dollars for research and development. Unless good encryption is employed, they can make copies of the computer 'secrets' without leaving any trace or clue that they even compromised such secrets.
Lets face it.
Most written communications today are created on computers. Most of these computers are not secure and to make matters worse many computers involved are portable notebook computers. File encryption helps here also. An Internet firewall is essentially one or more systems that control access between computer networks. In this regard, the Internet is nothing more than a very large computer network.