Critique of the Clipper Chip

April 1993 letter from Sameer Parekh:

The Clinton administration on Friday unveiled their plan for establishing a standard data encryption system for voice communications. President Clinton says that he wants to bring the United States into the twenty-first century. This proposal is bringing us to 1984. I will mention first the technical reasons why the system is inadequate.

The encryption algorithim is classified; only a select group of people will be allowed to examine the algorithim for flaws. The members of the cryptographic community continually and persistently emphasize that the only way to ensure security in a cryptographic system is to have as many people as possible analyze and try to break it for as long as possible. A system which has been examined by a small segment of the population should not be trusted.

Release of the algorithim is crucial to verification of a good encryption method. The earlier Data Encryption Standard (DES) for data storage encryption was a very strong standard; the academic world examined it and after a number of months found weaknesses, spawning the now-standard "triple-DES" system which is more secure.

From what little is known about the encryption system, it appears to be a weak system. Such a weak system lends itself to easy decryption by an unauthorized party. It would lend a false sense of security to laypersons in the field who do not realize that a key of such simplicity could be cracked easily by any talented criminal. The necessarily secure communications between a doctor and his patient could be thus breached. If the system were strong, the government would use it for internal use, but according to the AT&T release, the government will not be using the same chip which is marketed to consumers.

Apart from the technical flaws in the system, there are many political problems with this big brother proposal. First, there is the assumption that the government has a right to spy on its own citizens. The proposal for this wiretap chip includes the registration of keys with two escrow agencies. This proposal is purported to allow law enforcement to keep track of "terrorists" and "drug-dealers." The first flaw in this key-escrow system is that no self-respecting criminal will use a cryptography system which can be easily tapped by law enforcement officials -- they will use strong cryptography. The only people who may end up using the wiretap encryption system will be law-abiding laypeople who don't fully understand cryptography. (Law-abiding citizens who do understand cryptography will use strong cryptography to preserve their privacy from a talented criminal.)

The proposal states that in order to obtain the key of a wiretap chip user a law enforcement agency must first establish that they have a valid interest in the key. Translated out of legalese, that means that all a government agency will have to do to get access to all of the private communications, for example, between a lawyer and her client will be to fill out the necessary forms. Registering cryptographic keys with the government is similar to giving the IRS the keys to your house and filing cabinet. A criminal who wants access to the communications between a priest and confessor needs only to find a corrupt judge.

The chip is being manufactured exclusively by one company. The release stated that the Attorney shall request (i.e. coerce) telecommunication product manufacturers to use this product. This aspect of the system is a government-mandated monopoly. Such monopolies result in high prices and the elimination of market forces which drive the improvement of technology. (One needs only look at the state of the Soviet Union to see how the lack of market forces affects consumer technology.)

The system exposes our President's hypocrisy because of his campaign promise to protect womens' rights to privacy and that he will see a Supreme Court nominee who believes that the Bill of Rights guarantees a right to privacy. By mandating a weak cryptosystem he is reneging on his promise to provide privacy rights to the nation's citizenry. If Clinton supported a right to privacy to limit government interference with regards to abortions, he must limit government interference with regards to communication.

Another element of Clinton's hypocrisy lies in his promise to reduce the budget deficit. By introducing additional responsibilities for government agencies (keeping track of the millions of keys registered in escrow) he is only using our tax dollars to invade our privacy, tax dollars which are better spent lowering the budget deficit.

What I fear most from the proposal is that if the wiretap chip becomes the standard, strong cryptography will be declared illegal. If such is the case, then only criminals will have access to strong cryptography. As I have stated above -- the wiretap chip will not be used by criminals because of the obvious flaws in the crypto-system -- criminals will use strong crypto, while law-abiding citizens will have to use a system which can be easily defeated by any criminal.

Strong cryptography already exists for data communications, for free. Strong cryptography for voice communications for free is only a few months away for people who own a personal computer. There is no way that making strong cryptography illegal will stop it -- it will only turn otherwise law-abiding citizens into criminals.