Prying open the cryptographic door.

While conducting a court-authorized wiretap, an FBI agent encounters a completely unintelligible telephone conversation. Suspecting that this signal may actually represent encrypted speech, he sends it through an electronic device which establishes that a particular form of coding known as "escrowed" encryption is being used to scramble the conversation. The device also supplies the serial number of the integrated-circuit chip doing the scrambling at the suspect's telephone.

The agent submits this number and other documentation concerning the wiretap to two government agencies -- the National Institute of Standards and Technology and the Automated Services Division of the Treasury Department -- to obtain the "keys" required to decrypt this particular type of scrambled speech. When combined, the two keys enable the agent to decipher the conversation.

Last week, the Clinton administration announced several steps designed to make such a scenario possible. These actions, including the adoption of a voluntary federal standard for "key-escrow" encryption technology, represent an attempt to preserve the ability of law enforcement and national security agencies to intercept and decipher messages sent over computer and telephone lines.

First proposed last April, key-escrow encryption requires the use of a special chip (sometimes called Clipper) to encrypt digitized speech and data according to a classified mathematical formula developed by the National Security Agency (SN: 8/28/93, p.143). The scheme also provides a special master key, divided into two parts accessible only to authorized officials, to unlock an encrypted message.

If widely used, such a scheme would preserve the ability of government agencies to conduct authorized wiretaps. "We have long needed to rely on wiretaps to help protect society from some of its greatest dangers," insists Webster Hubbell, associate attorney general at the Justice Department. Officials say this capability is threatened by the rapidly increasing use of alternative, unbreakable encryption techniques.

Computer and communications companies, however, are concerned that customers will be reluctant to buy equipment to which the government holds a key. Groups such as Computer Professionals for Social Responsibility (CPSR) complain about potential threats to privacy and about the secrecy surrounding the federal government's internal review of cryptographic policy (SN: 6/19/93, p.394). "We believe that if this proposal and the associated standards go forward, even on a voluntary basis, privacy protection will be diminished, innovation will be slowed, government accountability will be lessened, and the openness necessary to ensure the successful development of the nation's communications infrastructure will be threatened," CPSR's Marc Rotenberg and 42 others warned in a Jan. 24 letter to President Clinton.

Despite this opposition, the Clinton administration decided to go ahead with its original plan, making essentially no concessions to critics.

"They decided to' completely ignore the public input that they had asked for," says Stephen T. Walker of Trusted Information Systems, Inc., in Glenwood, Md. Walker serves on the Computer System Security and Privacy Advisory Board, which last year held public hearings and solicited comments on the administration's proposal and made recommendations to the government.

Government officials hope that manufacturers will start incorporating this technology into telephones, modems, and other communications equipment sold to federal agencies. The Justice Department has already ordered about 8,000 encryption devices for its telephones.

"The government is going to spend a great deal of money buying equipment and setting up the key-escrow system, but it won't succeed," Walker predicts. Businesses will balk at buying such products for their own use, he says.

Meanwhile, the debate over cryptographic policy is sure to continue. "It's a complicated issue," says Lance J. Hoffman of George Washington University in Washington, D.C. "We're really trying to set in place our constitution for an electronic age."