Horst Feistel (January 30, 1915 – November 14, 1990) was born in Berlin Germany. In 1934 he moved to the United States. Feistel attended MIT, where he earned a bachelor’s of science degree in physics. He then attended Harvard where, in 1942, he earned a master’s degree, also in physics. Feistel was granted US citizenship in 1944. The following day he gained security clearance and began working at the US Air Force Cambridge Research Center. After Feistel's work with the US Airforce he began working at MIT. While at MIT he worked doing research for the Computer Science Department in 1968 before switching to research for the Mathematical Sciences Department in 1971. During this time Feistel met A. Adrian Albert. Albert felt that Feistel’s talents were not being allowed to flourish in his current position and suggested that Feistel seek employment at IBM. During Feistel's time at IBM he began working with block ciphers to encrypt data.
Lucifer
While working at IBM Feistel began writing programs in APL. Using the APL programming language, Feistel developed block ciphers that would encrypt data sent by computers. Feistel originally named this block cipher DEMONSTRATION, but due to the APL’s character limit the name was shortened to DEMON. Feistel then changed the name to LUCIFER as he thought it was a catchier name. LUCIFER was set up to scramble a block of data by performing several encipherment steps on the data. The original LUCIFER cipher enciphered 128 bits and used a 128 bit key. The LUCIFER cipher was originally used to encrypt data in banking and was used in ATM’s in Essex, England.
NSA and the Data Encryption Standard
IBM took the LUCIFER Cipher and worked upon it to create the Data Encryption Standard, which was a commercial version of LUCIFER, approved in 1976. The Data Encryption Standard was modified at the request of the NSA. Changes from the original LUCIFER to Data Encryption Standard included changing the algorithm for the encryption and shortening the key size from 128 bits to 56 bits. After these changes Lucifer had been changed to the Data Encryption Standard and was now accepted by the NSA and ready for wide use.
Legacy and Influence
For years the Data Encryption Standard was used to encrypt all sorts of data. Originally built for and used by banks, people quickly realized that this encryption could be used for all kinds of e-commerce and sensitive electronic data. Original discovery of the NSA’s changes to the system created outrage among some who believed that the shorter key size would lead to decreased security. Because of this many people began examining the Data Encryption Standard, either trying to break it or to find out what the changes made by the NSA had done. With this outcry and increased scrutiny, the modern field of cryptography rose as people gained new passion for electronic data encryption. Finally, in 1999 after years of scrutiny and outrage, it was discovered that the changes made by the NSA had actually improved the security of the Data Encryption Standard, although by this time a field of digital cryptography and data encryption had bloomed as the need for cyber security became clear to everyone.
Horst Feistel
Table of Contents
Early Life - IBM
Horst Feistel (January 30, 1915 – November 14, 1990) was born in Berlin Germany. In 1934 he moved to the United States. Feistel attended MIT, where he earned a bachelor’s of science degree in physics. He then attended Harvard where, in 1942, he earned a master’s degree, also in physics. Feistel was granted US citizenship in 1944. The following day he gained security clearance and began working at the US Air Force Cambridge Research Center. After Feistel's work with the US Airforce he began working at MIT. While at MIT he worked doing research for the Computer Science Department in 1968 before switching to research for the Mathematical Sciences Department in 1971. During this time Feistel met A. Adrian Albert. Albert felt that Feistel’s talents were not being allowed to flourish in his current position and suggested that Feistel seek employment at IBM. During Feistel's time at IBM he began working with block ciphers to encrypt data.Lucifer
While working at IBM Feistel began writing programs in APL. Using the APL programming language, Feistel developed block ciphers that would encrypt data sent by computers. Feistel originally named this block cipher DEMONSTRATION, but due to the APL’s character limit the name was shortened to DEMON. Feistel then changed the name to LUCIFER as he thought it was a catchier name. LUCIFER was set up to scramble a block of data by performing several encipherment steps on the data. The original LUCIFER cipher enciphered 128 bits and used a 128 bit key. The LUCIFER cipher was originally used to encrypt data in banking and was used in ATM’s in Essex, England.NSA and the Data Encryption Standard
IBM took the LUCIFER Cipher and worked upon it to create the Data Encryption Standard, which was a commercial version of LUCIFER, approved in 1976. The Data Encryption Standard was modified at the request of the NSA. Changes from the original LUCIFER to Data Encryption Standard included changing the algorithm for the encryption and shortening the key size from 128 bits to 56 bits. After these changes Lucifer had been changed to the Data Encryption Standard and was now accepted by the NSA and ready for wide use.Legacy and Influence
For years the Data Encryption Standard was used to encrypt all sorts of data. Originally built for and used by banks, people quickly realized that this encryption could be used for all kinds of e-commerce and sensitive electronic data. Original discovery of the NSA’s changes to the system created outrage among some who believed that the shorter key size would lead to decreased security. Because of this many people began examining the Data Encryption Standard, either trying to break it or to find out what the changes made by the NSA had done. With this outcry and increased scrutiny, the modern field of cryptography rose as people gained new passion for electronic data encryption. Finally, in 1999 after years of scrutiny and outrage, it was discovered that the changes made by the NSA had actually improved the security of the Data Encryption Standard, although by this time a field of digital cryptography and data encryption had bloomed as the need for cyber security became clear to everyone.References:
http://www.cs.ucsb.edu/~konheim/Feistel%20Talk%20-2Final.pdf ,University of California, Santa Barbara, Konheim
http://www.quadibloc.com/crypto/co0401.htm , John Savard, quadibloc.com
https://www.schneier.com/blog/archives/2004/10/the_legacy_of_d.html ,Bruce Schneier, Schneier on Security
https://www.britannica.com/topic/Data-Encryption-Standard ,Gustavus J. Simmons, Encyclopedia Britannica