Protecting data from prying eyes

The banks are closed and you want to check how much money is in your ac- count. You put your plastic card into an automated teller machine and the bad news is printed out. Does anybody else know? Your employer"s personnel department has just put all its records on com- puter, including details of your employment history, your health, your edu- cation, and even family in- formation. Once it was kept in a locked cabinet and only one person had the key. Now terminals all over the company, even in other branches, are con- nected to the same com- puter. Who can read your personal files? Your company has in- stalled an up-to-the minute office automation system. Senior staff dial it up every evening and use their own home computers to analyse sales data and work on new product plans. How do they know that rival companies are not dialling the same computer and stealing in- formation? Espionage or accident In each case it is imposs- ible to give an accurate answer. Because of its very natu...