By Simson L. Garfinkel
As the U.S. Senate debates granting the Federal Bureau of Investigation new powers to wiretap personal communications three West Coast computer programmers have planned their own pre-emptive strike: a free program, distributed on the Internet, that renders legal and illegal wiretaps useless.
The programmers, Bill Dorsey of Los Altos, Pat Mullarky of Bellevue, Wash., and Paul Rubin of Milpitas, have released a program that turns ordinary IBM-compatible personal computers into an untappable secure telephone. It uses an encryption algorithm called ''triple-DES'' that is widely believed to be unbreakable.
''Electronic surveillance by the government is on the rise,'' says Dorsey, the group's lead programmer. ''There also exists an equally large threat from the privatesector as well: industrial espionage. Foreign governments are interested in wiretapping and getting information out of our high-tech firms.''
Called Nautilus, the program is being released as an attack on the Clinton administration's national encryption standard, the Clipper chip. Civil rights groups have criticized the Clipper initiative, since the federal government holds a copy of every chip's master key and can use that key to decrypt -- or decode -- any Clipper-encrypted conversation. But since the keys used by Nautilus to encrypt conversations are created by users, the government does not have a copy.
Nautilus has another advantage over Clipper: Whereas AT&T's Clipper-equipped Telephone Security Devices Model 3600 costs $1,100, Nautilus is free program.
''You don't need any special expensive hardware for it. You just use ordinary PCs,'' says Rubin.
The name ''Nautilus'' was taken from Captain Nemo's submarine in the Jules Verne novel, ''20,000 Leagues Under the Sea.'' But whereas Nautilus the sub was used to sink Clipper ships, the programmers hope that their creation will sink Clipper chips.
To use Nautilus, both participants must have a copy of the program and an IBM PC-compatible computer equipped with a Sound Blaster card and a high-speed modem. The two participants must also agree upon a series of words called a ''pass phrase,'' which is used to encrypt the conversation. Both participants run the program and type in the pass phrase; one person instructs their computer to place the telephone call, the other instructs their computer to answer.
Once the call is in progress, either user must press a key on their computer in order to speak, similar to using a hand-held radio. But unlike walkie-talkies, the users can interrupt each other.
Such innovations could lead to conversations that would be practically foolproof from eavesdropping, either by pranksters or the government. It could become invaluable in future years to financial institutions and other corporations involved in sensitive negotiations.
''It will certainly be beneficial to many citizens and many other users of it,'' says Jim Kallstrom, assistant director of the Federal Bureau of Investigation's New York field office. ''I suspect that it also will be beneficial, unfortunately, to criminals.
''I would hope the extremely enterprising and smart people that we have in this country would work toward solutions that would not only protect the communication of citizens . . . but would also allow the law enforcement objectives to be maintained.''
Rubin stressed that while Nautilus was a challenge to write, it ''isn't rocket science.'' Much of the program, in fact, was assembled from parts that already were available on the Internet, the worldwide network of computer networks. It will even be easier to construct programs similar to Nautilus once Microsoft releases its computer telephony system for Windows 95. ''It will be impossible to keep a program like Nautilus out of the hands of people who want it,'' Rubin said.
Gene Spafford, a professor of computer science at Purdue University who is an expert on computer security, said: ''It will be interesting to see what reaction this provokes from the government.'' Nevertheless, Spafford said, in order for encryption to be widely adopted, it will have to be ''built into the phones.''
Dorsey said that anybody in the United States who has Internet access can download the program. For the instructions, use the Internet FTP command to connect to the computer FTP.CSN.ORG. Change to the ''mpj'' directory and retrieve the file called README. Use a text editor to read the README file, which contains some fairly complex instructions on how to get the actual Nautilus file.
This computer has been set up so that the program cannot be downloaded by people located outside the United States. ''I intend to follow all laws regarding the release of cryptography,'' he said.