Horst Feistel (January 30, 1915 – November 14, 1990) was a German-American

cryptographer Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or '' -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adv ...

who worked on the design of

ciphers In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An alternative, less common term is ''encipherment''. To encipher or encode ...

at IBM, initiating research that culminated in the development of the

Data Encryption Standard The Data Encryption Standard (DES ) is a symmetric-key algorithm for the encryption of digital data. Although its short key length of 56 bits makes it too insecure for modern applications, it has been highly influential in the advancement of cr ...

(DES) in the 1970s. The structure used in DES, called a

Feistel network In cryptography, a Feistel cipher (also known as Luby–Rackoff block cipher) is a symmetric structure used in the construction of block ciphers, named after the German-born physicist and cryptographer Horst Feistel, who did pioneering research whi ...

, is commonly used in many

block ciphers In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called ''blocks''. Block ciphers are specified elementary components in the design of many cryptographic protocols and are widely used to encry ...

Life and work

Feistel was born in

Berlin Berlin is Capital of Germany, the capital and largest city of Germany, both by area and List of cities in Germany by population, by population. Its more than 3.85 million inhabitants make it the European Union's List of cities in the European U ...

Germany Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the sou ...

in 1915, and moved to the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

in 1934. During

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

, he was placed under house arrest, but gained US citizenship on 31 January 1944. The following day he was granted a security clearance and began work for the US

Air Force Cambridge Research Center The Air Force Research Laboratory (AFRL) is a scientific research organization operated by the United States Air Force Materiel Command dedicated to leading the discovery, development, and integration of aerospace warfighting technologies, pl ...

(AFCRC) on

Identification Friend or Foe Identification, friend or foe (IFF) is an identification system designed for command and control. It uses a transponder that listens for an ''interrogation'' signal and then sends a ''response'' that identifies the broadcaster. IFF systems usua ...

(IFF) devices until the 1950s. He was subsequently employed at

MIT The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

Lincoln Laboratory The MIT Lincoln Laboratory, located in Lexington, Massachusetts, is a United States Department of Defense federally funded research and development center chartered to apply advanced technology to problems of national security. Research and de ...

, then the

MITRE The mitre (Commonwealth English) (; Greek: μίτρα, "headband" or "turban") or miter (American English; see spelling differences), is a type of headgear now known as the traditional, ceremonial headdress of bishops and certain abbots in t ...

corporation. Finally, he moved to IBM, where he received an award for his cryptographic work. His research at IBM led to the development of the

Lucifer Lucifer is one of various figures in folklore associated with the planet Venus. The entity's name was subsequently absorbed into Christianity as a name for the devil. Modern scholarship generally translates the term in the relevant Bible passage ...

and

(DES) ciphers. Feistel was one of the earliest non-government researchers to study the design and theory of

block cipher In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called ''blocks''. Block ciphers are specified cryptographic primitive, elementary components in the design of many cryptographic protocols and ...

s. Feistel lent his name to the

construction, a common method for constructing block ciphers (for example DES). Feistel obtained a

bachelor's degree A bachelor's degree (from Middle Latin ''baccalaureus'') or baccalaureate (from Modern Latin ''baccalaureatus'') is an undergraduate academic degree awarded by colleges and universities upon completion of a course of study lasting three to six ...

, and his

master's A master's degree (from Latin ) is an academic degree awarded by universities or colleges upon completion of a course of study demonstrating mastery or a high-order overview of a specific field of study or area of professional practice.

at Harvard, both in

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which rel ...

. He married Leona (Gage) in 1945, with whom he had a daughter, Peggy.

Notes

References

Whitfield Diffie Bailey Whitfield 'Whit' Diffie (born June 5, 1944), ForMemRS, is an American cryptographer and mathematician and one of the pioneers of public-key cryptography along with Martin Hellman and Ralph Merkle. Diffie and Hellman's 1976 paper ''New Dire ...

, Susan Landau (1998). ''Privacy on the Line: The Politics of Wiretapping and Encryption''. *Horst Feistel, "Cryptography and Computer Privacy." ''

Scientific American ''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it i ...

'', Vol. 228, No. 5, 1973
(JPEG format scanned)
*Horst Feistel, H, W. Notz, J. Lynn Smith. "Some cryptographic techniques for machine-to-machine data communications." IEEE Proceedings, 63(11), 1545–1554, 1975. * Levy, Steven. '' Crypto: How the Code Rebels Beat the Government—Saving Privacy in the Digital Age'', 2001.

External links

* {{DEFAULTSORT:Feistel, Horst 1915 births 1990 deaths People from Berlin German emigrants to the United States MIT Department of Physics alumni Harvard Graduate School of Arts and Sciences alumni Modern cryptographers IBM employees IBM Research computer scientists German computer scientists Mitre Corporation people MIT Lincoln Laboratory people