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.2.(p.52) For quite some time, communications security was poor in parts of the US government(particularly the Department of State) that lacked access to the services of the militarycryptographers.3.(p.54) A 2400-bit-per-second mode of operation is one of the Minimum Essential Requirements ofthe third generation secure telephone unit (STU-III), which went into use in 1987.4.(p.55) There appear to have been rotor-based voice systems, but these were probably analogscramblers that filtered the signal into several bands employed rotors to shuffle the bands in aconstantly changing pattern.5.(p.56) A small number of serious books were published in Europe, in particular Eyraud 1959.6.(p.56) Papers on points pure of mathematics whose cryptographic inspiration is clearly visible topeople familiar with the subject were written by Andrew Gleason, Marshall Hall, W.H.Mills, andpresumably others.7.(p.56) Kennedy's orders do not mention cryptography, but require that US nuclear weapons be putunder positive control of the National Command Authority, wherever in the world they may belocated.What this came down to was that they could not be armed by anyone unable to send themproperly encrypted messages.The key component in this program is the permissive action link,which, in effect, issues an encrypted order to a nuclear weapon.Earlier PALs used conventionalcryptography; more recent ones use public-key techniques.8.(p.57) Source: private conversations between Diffie and Feistel.9.(p.57) Eventually, in the late 1960s, the cryptographic system Feistel's group designed wasbundled together with the existing modes of operation of the Mark X IFF.The result was called theMark XII (there never was an XI), and its cryptographic mode was Mode 4.The Mark XII isemployed extensively by the military aircraft of the US and its allies.10.(p.57) Source: private conversations between Diffie and Carl Engelman of Mitre in the 1970s andbetween Diffie and Horst Feistel circa 1990. 11.(p.58) The importance of the Federal Information Processing standards is illustrated by FIPS 1,the American Standard Code for Information Interchange or ASCII.The government's adoption ofthis code, which is ubiquitous today, made it dominant over the rival EBCDIC encoding used byIBM, then the world's largest computer manufacturer.12.(p.59) The one in the 2984 is now called the Alternate Encryption Technique.At least two otherIBM systems were also called Lucifer.One designed by John Lynn Smith, but never developed into aproduct, presents the fullest exposition of Feistel's techniques (Smith 1971).Another system calledLucifer was used only as a tutorial device (Feistel 1973).13.(p.59) At NSA, Howard Rosenblum, Deputy Director for Communication Security, and DougHogan; at NBS, Ruth Davis, Seymour Jeffery, and Dennis Branstad.14.(p.59) NOFORN means "No foreign dissemination allowed." This is an odd designation for manyNSA algorithms, since several of the most important are NATO standards.15.(p.60) In testimony to congress, NSA Director Bobby Ray Inman asserted that public keycryptography had been discovered at NSA 10 years earlier.The work in question appears to be thatof three GCHQ employees done about 1972.The precise scope of the British discoveries has yet tocome out, but in the words of one of the three "You did much more with it than we did." It appearsthat Inman preferred to give credit to three Brits with clearances than three Yanks without.16.(p.61) The term is a misnomer because the items exchanged are not actually keys.Incontemporary literature, the more precise terms key negotiation or key agreement are preferred, butthe original terminology persists.17.(p.62) In the early 1970s, for example, secrecy orders were placed on some of the inventions ofHorst Feistel, nucleus of the cryptographic research group at IBM.18.(p.62) Secrecy orders are often helpful to a company because they delay the granting (and thusexpiration) of its patents until a time when the invention is more appropriate to the market.In 1939the famous actress Hedy Lamarr filed for the first patent on frequency hopping radio (Markey 1942).Had this application been kept secret until the 1970s, when spread spectrum technology emergedfrom military into civilian applications, Hedy Lamarr would be enjoying a much more comfortableretirement. 19.(p
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