The Clipper chip is a chipset that was developed and promoted by the U.S. Government as an encryption device to be adopted by telecommunications companies for voice transmission. A chipset is a group of integrated circuits (chips) that are designed to work together, and are usually marketed as a single product. ... In cryptography, encryption is the process of obscuring information to make it unreadable without special knowledge. ...

Background

In the early 1990s, the increasing popularity of the Internet and of digitized communications caused concern to many in the law enforcement community because of the implications for wiretapping. Before the 1980s, in the days of analog telephone system equipment, it was a simple task, from a technical standpoint, to eavesdrop on a telephone conversation; a police officer could attach two alligator clips to the appropriate circuit, and listen in at will. The installation of electronic switching systems in the phone network made this a more complicated task, but ultimately the data transmitted was a simple unencrypted signal that, once accessed, could be understood immediately. The 1990s decade refers to the years from 1990 to 1999, inclusive, the last decade of the 20th Century. ... For the band, see The Police. ... Telephone tapping or Wire tapping/ Wiretapping (in US) describes the monitoring of telephone conversations by a third party, often by covert means. ... The 1980s decade refers to the years from 1980 to 1989, inclusive. ... A crocodile clip or alligator clip is a clip named for its resemblance to a crocodiles jaws. ... In telecommunications, an electronic switching system (ESS) is: A telephone switching system based on the principles of time-division multiplexing of digitized analog signals. ...

With the continuing increase in computer speed and the development of such public-key cryptography algorithms as RSA, it became evident that in the short term, telephones could be invented which would digitize voice data, and then transmit that digital data using strong encryption, such that eavesdropping would be impossible. The previously valuable technique of wiretapping would be useless. Public key cryptography is a form of cryptography which generally allows users to communicate securely without having prior access to a shared secret key. ... In cryptography, RSA is an algorithm for public-key encryption. ... Digitizing, or digitization, is the process of turning an analog signal into a digital representation of that signal. ...

Key Escrow

The Clipper chip, announced in 1993, used a data encryption algorithm invented by the National Security Agency of the U.S. Government; this algorithm was classified secret so that it could not be subjected to the peer review that was usual in the encryption research community. Part of the technique was that when a telephone with a Clipper chip was manufactured, a password, or "key", that could be used to decrypt the data was to be given to the government in "escrow". (The newly formed Electronic Frontier Foundation preferred the term "key surrender" to emphasize what the user was really doing.) If government agencies "established their authority" to listen to a communication, then the password would be given to those government agencies, who could then decrypt all data transmitted by that particular telephone. Key escrow is an arrangement in which the keys needed to decrypt encrypted data are held in escrow by a third party, so that someone else (typically government agencies) can obtain them to decrypt messages which they suspect to be relevant to national security. ... Cite error 4; Invalid call; no input specified 1993 (MCMXCIII) was a common year starting on Friday of the Gregorian calendar and marked the Beginning of the International Decade to Combat Racism and Racial Discrimination (1993-2003). ... Flowcharts are often used to represent algorithms. ... NSA seal The National Security Agency / Central Security Service (NSA/CSS) is believed to be the largest United States government intelligence agency. ... A password is a form of secret authentication data that is used to control access to a resource. ... A key is a piece of information that controls the operation of a cryptography algorithm. ... Escrow is a legal arrangement whereby a thing (often money, but sometimes other property such as art, a deed of title, or software source code) is delivered to a third party (called an escrow agent) to be held in trust pending a contingency or the fulfillment of a condition or... The EFF uses the blue ribbon as symbolism for their Free Speech defense. ...

Although the algorithm was classified, the government did state that it used an 80-bit key, that the algorithm was symmetric, and that it was similar to the DES algorithm. The initial cost of the chips was said to be $16 (unprogrammed) or $26 (programmed), with its logic designed by Mykotronx, and fabricated by VLSI Technology, Inc General Designer(s) IBM First published 1975 (January 1977 as the standard) Derived from Lucifer (cipher) Cipher(s) based on this design Triple DES, G-DES, DES-X, LOKI89, ICE Algorithm detail Block size(s) 64 bits Key size(s) 56 bits Structure Feistel network Number of rounds 16 Best... VLSI Technology, Inc (Nasdaq: VLSI) was an American company that designed and manufactured custom chips. ...

Backlash

In announcing the Clipper chip initiative, the government did not state that it intended to try to make data encryption illegal, but several statements seemed to point in this direction, such as one paragraph from the government's fact sheet: In cryptography, encryption is the process of obscuring information to make it unreadable without special knowledge. ...

In making this decision, I do not intend to prevent the private sector from developing, or the government from approving, other microcircuits or algorithms that are equally effective in assuring both privacy and a secure key-escrow system.

Such "electronic civil liberties" organizations as the Electronic Privacy Information Center and the Electronic Frontier Foundation challenged the Clipper chip proposal, saying that it would have the effect not only of subjecting citizens to increased and possibly illegal government surveillance, but that the strength of the Clipper chip's encryption could not be evaluated by the public, as its design was classified secret, and that therefore individuals and businesses might be hobbled with an insecure communications system. Furthermore, it was pointed out, while American companies could be forced to use the Clipper chip in their encryption products, foreign companies could not, and presumably phones with strong data encryption would be manufactured abroad and would spread throughout the world and into the United States, defying the point of the whole exercise, and materially damaging U.S. manufacturers en route. Then-Senator John Ashcroft (Republican-Missouri) was a leading opponent of the Clipper chip proposal, arguing in favor of the individual's right to encrypt messages and export encryption software. Electronic Privacy Information Center or EPIC is a public interest research group in Washington D.C.. It was established in 1994 to focus public attention on emerging civil liberties issues and to protect privacy, the First Amendment, and constitutional values. ... The EFF uses the blue ribbon as symbolism for their Free Speech defense. ... Surveillance is the monitoring of behavior. ... John David Ashcroft (born May 9, 1942) was the 79th Attorney General of the United States. ... Republican is a term used generally to describe a number of different organisations, principles, or political movements, and/or the persons supporting these. ... State nickname: The Show Me State Official languages English Capital Jefferson City Largest city Kansas City (largest metropolitan area is Saint Louis) Governor Matt Blunt (R) Senators Kit Bond (R) Jim Talent (R) Area  - Total  - % water Ranked 21st 69,709 mi²; 180,693 km² 1. ...

Vulnerability

In 1994, Matt Blaze published the paper Protocol Failure in the Escrowed Encryption Standard[1]. The Clipper's escrow system has a serious vulnerability; the hash for the 128-bit LEAF field was too short (mere 16 bits), allowing a brute force attack to find another value of LEAF that would give the same hash, but won't yield the correct keys after the escrow attempt. 1994 (MCMXCIV) was a common year starting on Saturday of the Gregorian calendar, and was designated the International year of the Family. ... Matt Blaze is a researcher in the areas of secure systems, cryptography, and trust management. ... The EFFs US$250,000 DES cracking machine contained over 18,000 custom chips and could brute force a DES key in a matter of days — the photograph shows a DES Cracker circuit board fitted with several Deep Crack chips In cryptanalysis, a brute force attack is a method...

Dead on the Vine

The Clipper chip was not embraced by consumers or manufacturers, and the chip itself was a dead issue by 1996. The government continued to press for key escrow by using incentives to manufacturers, allowing more relaxed export controls if key escrow were part of cryptographic software that was exported. These attempts were largely mooted by the widespread use of such strong cryptographic technologies as PGP, which was not under the control of the U.S. government. 1996 (MCMXCVI) is a leap year starting on Monday of the Gregorian calendar, and was designated the International Year for the Eradication of Poverty. ... Key escrow is an arrangement in which the keys needed to decrypt encrypted data are held in escrow by a third party, so that someone else (typically government agencies) can obtain them to decrypt messages which they suspect to be relevant to national security. ... PGP is a computer program which provides cryptographic privacy and authentication. ...

In 1998, the encryption algorithms used in Clipper were declassified: Skipjack and KEA. 1998 (MCMXCVIII) is a common year starting on Thursday of the Gregorian calendar, and was designated the International Year of the Ocean. ... In cryptography, Skipjack is a block cipher — an algorithm for encryption — developed by the US National Security Agency (NSA). ...