Clipper technology attempts to balance these needs by using escrowed
keys. The idea is that communications would be encrypted with a secure
algorithm, but the keys would be kept by one or more third parties (the
``escrow agencies''), and made available to law-enforcement agencies
when authorized by a court-issued warrant. Thus, for example, personal
communications would be impervious to recreational eavesdroppers, and
commercial communications would be impervious to industrial espionage,
and yet the FBI could listen in on suspected terrorists or gangsters.
Clipper has been proposed as a U.S. government standard; it would then be used by anyone doing business with the federal government as well as for communications within the government. For anyone else, use of Clipper is strictly voluntary. AT&T has announced a secure telephone that uses the Clipper chip.