In addition the growth of computer and satellite communications, which has escalated the potential for hacking and interception, has made it ever more necessary for businesses to protect their data. Because new cryptosystems are cheap and easy to use, multinational corporations are increasingly encrypting their satellite messages, e-mail, and data banks.
An automated teller machine (ATM) encrypts the account numbers and requests that it transmits to the bank's mainframe, which similarly encrypts the balances and withdrawal authorizations that it sends back to the ATM. Subscription television jumbles its signals so only those who have paid for a decoder can receive clear pictures.
Perhaps out of fear of negative publicity if exposed, companies have rarely intercepted a competitor's messages. Encrypted bank messages are not known to have been solved, probably because there are easier ways to get the money. At least one government has read at least one oil company's encrypted messages, however, and used the information in bargaining over an exploration contract.
