It was invented by horst feistel in his design of lucifer fei73, and has been used in many block cipher designs since then. He advised the young horst feistel, who felt his interest in exploring cryptography was being stifled at the national security agency, to seek. Des nbs77, feal sm88, gost gost89, khufu and khafre. In the 1970s, a crypto algorithm called lucifer algorithm, devised by horst feistel, was evaluated and after some changes to the internal functions and reducing the key size from 112 bits to 56 bits, the complete algorithm that became the data encryption standard. He lent his name to the feistel network construction, a common method for constructing block ciphers for example des. At about the same time, horst feistel, who had earlier worked on identification friend or foe devices for the air force, took his lifelong passion for. We describe feistels successful escape from nazi germany, his university training in physics in zurich and in boston, and the career change to cryptography. The invention of feistel ciphers is usually credited to ibms horst feistel, who cocreated the first publicly known encryption algorithm of this type, lucifer, in the early 1970s. A feistel network is a cryptographic technique used in the construction of block cipherbased algorithms and mechanisms. Feistel cipher simple english wikipedia, the free encyclopedia.
By horst feistel scientific american, may 1973, volume 228, no 5, pp. Horst feistel ibm created the lucifer block cipher as a result of research hobby. To avoid provoking the authorities, he kept quiet about his interest in cryptography until after the war, when he went to work for the united states air force, pursuing his interest in developing new ciphers. In the 1970s, horst feistel developed a family of ciphers, the feistel ciphers, while working at ibms watson research laboratory.
Horst feistel designs lucifer at ibm key 128 bits, block 128 bits. Feistel cipher structure horst feistel devised the feistel cipher based on concept of invertible product cipher. Feistel network is a standard form for iterating a function f on parts of a message producing invertible transformation uaes rijndael is related also a block cipher with repeated rounds not a feistel network feistel network. Cryptography and network security chapter 3 fifth edition by william stallings lecture slides by lawrie brown with edits by rhb chapter 3 block ciphers and the data encryption standard all the afternoon mungo had been working on sterns code, principally with the aid of the latest messages which he had copied down at the nevin square drop. Chapter 2 the data encryption standard des as mentioned earlier there are two main types of cryptography in use today symmetric or secret key cryptography and asymmetric or public key cryptography. Feistel cipher structure virtually all conventional block encryption algorithms, including des, have a structure first described by horst feistel of ibm in 1973 specific realization of a feistel network depends on the choice of the following parameters and features. This paper documents the early life of horst feistel, in particular, the events shaping his career. It was selected by the national bureau of standards as an official federal information processing standard fips for the united states in 1976 and which has subsequently enjoyed widespread use internationally. Quantum attacks on some feistel block ciphers 3 comparison with bonnetain et al. Cryptography and computer privacy by horst feistel scientific american, may 1973, volume 228, no 5, pp.
He was a germanborn cryptographer who worked on the design of ciphers at ibm. It allows a cryptographic system to use the same algorithm for encryption and decryption of the data. Beginning in 1952, a group under the direction of horst feistel at the air force cambridge research center began to apply cryptography to the military problem of distin. Most modern block encryption algorithms use the feistel structure. A cryptographic system based on feistel cipher structure uses the same algorithm for both encryption and decryption. It is based on a symmetrickey algorithm that uses a 56bit key. Feistal cipher structure free download as powerpoint presentation. Developed in the early 1970s at ibm and based on an earlier design by horst feistel. One popular class of the modern iterative blockciphers is the feistel ciphers named so after horst feistel cryptanalyst who worked with the ibm crypto group in the early 1970s. Horst feistel born in east berlin on january 30, 2015.
Actually, the structure proposed by feistel is based on the shannon structure which was proposed in 1945. The structure used in des, called a feistel network, is commonly used in many block ciphers. Feistel was investigated as a possible spy and placed under house arrest until 1944. Horst feistel, don coppersmith, alan hoffman, alan konheim feistel network based on figure 4. In the united states cryptography policy and information about cryptography were largely the province of. It is no surprise, then, that new forms of cryptography came soon after the widespread. Block ciphers basically map n bits of input to n bits of output. In cryptography, a feistel cipher is a symmetric structure used in the construction of block ciphers, named after the german ibm cryptographer horst feistel. And we talked about two canonical examples, triple des and aes. The feistel network later became the basis for many encryption schemes, among them the data encryption standarddes is the most popular one. Feistel cipher lucifer is simply a product cipher that consist of a network for symmetric block ciphers. Feistel ciphers balanced and unbalanced represent the most popular symmetric cipher type in modern cryptography. Feistel cipher structure framework for symmetric block ciphers, and it.
A trickle of new cryptographic papers began to be written. If f is a pseudorandom function indexed by key k 1, transforms rightside data into a pseudoonetimepad for leftside. Feistel cipher is a structure proposed by a horst feistel which was considered while developing many symmetric block ciphers. The structure used in des, called a feistel network, is comm. Data encryption standarddes is a feistel cipherblock length is 64 bitkey length is 56 bit. We also give a brief story of these ciphers and basic security results. Data encryption standard des and simplified des sdes. Feistel works by applying a function of the right side to the left side, i. Data encryption standard des fiestel ciphers the cryptographer horst fiestel was one of the designers of. The feistel cipher or feistel network is named after horst feistel, who developed it while working at ibm.
Named after the ibm cryptographer horst feistel and. A cryptographic system based on feistel structure uses the same basic algorithm for both encryption and decryption. Feistel ciphers security proofs and cryptanalysis valerie. Until the 1970s, cryptography was largely doneonly in the government. Horst feistel was the leader of the ibm team that worked in late. Creativity in computer science horst feistel horst feistel is the son richard and helene feistel of frankfurtoder germany. Cryptography and network security chapter 3 fifth edition. Horst feistel january 30, 1915 november 14, 1990 was a germanborn cryptographer who worked on the design of ciphers at ibm, initiating research that culminated in the development of the data encryption standard des in the 1970s.
Later, the concept was identified by shannons property of confusion. Neverthe less, the techniques employed in secret communication remained largely pencil by horst feistel andpaper operations. Inf3510 information security university of oslo spring. Horst feistel was born in berlin in 1915 and moved to the usa in 1934, where he was placed under house arrest from 1939 until the end of world war 2 in 1945.
As shown in figure 2, the feistel structure consists of multiple. Block ciphers and the data encryption standard purdue engineering. A feistel network is also known as a feistel cipher. Data encryption standard des, an early data encryption standard endorsed by the u. Infobox block cipher the data encryption standard des is a block cipher that uses shared secret encryption. Ggx x in order to achieve the very comfortable similarity of encryption and. If a block cipher or cryptographic hash function does not satisfy the avalanche effect to a significant degree, then it has poor randomization. This is equivalent to right2 left1 fright1, left2 right1 but that formulation works better in languages with parallel or destructuring assignment which java doesnt have. With symmetric encryption, we can encrypt datawith an exclusive or, a left circular shiftand a number 2 pencil. A large set of block ciphers use the scheme, including the data encryption standard. Horst feistel was a german born researcher who worked in ibm. The feistel structure has the advantage that encryption and decryption operations are very similar, even. The term avalanche effect was first used by horst feistel feistel 1973.
In part 2, we describe generic attacks on feistel ciphers. His creativity led to the development of todays highgrade cryptographic algorithms. In memory of horst feistel prof bill buchanan obe medium. Later, lucifer became a major ibm initiative, and ibm revised it, named it dsd1. Chapter 3 block ciphers and the cryptography and data. E a brief history of cryptography policy cryptography. Foreword by whitfield diffie preface about the author chapter. A large proportion of block ciphers use the scheme, including the data encryption standard des. One popular class of the modern iterative blockciphers is the feistel ciphers named so after horst feistelcryptanalyst who worked with the ibm crypto group in the early 1970s. E a brief history of cryptography policy cryptographys. Important civilian postwwii, pre1970 cryptography work done at ibm key players. In the united states cryptography policy and information about cryptography were largely the province of the national security agency nsa until the 1970s. Basic concepts in cryptography fiveminute university.
Many other slides are from dan bonehsjune 2012 coursera crypto class. Horst feistel january 30, 1915 november 14, 1990 was a germanamerican cryptographer. Nov 21, 2018 this paper documents the early life of horst feistel, in particular, the events shaping his career. One round uscheme requires function fr i1,k i computation for ki e. It was phased out at the start of the 21st century by a more secure encryption standard, known as the advanced. In 1973, a scientist working for ibm, horst feistel, developed the feistel cipher. Scribd is the worlds largest social reading and publishing site. He is famous for leading the ibm team whose design became the data encryption standard or des. It was highly influential in the advacement of modern cryptography in the academic world. Apr 08, 2020 46 years after the scientific american article may 1973, volume 228, no 5, alan konheim, the founding chair of the ucsbs computer scientific dept wrote an article on horst feistel in journal of cryptographic engineering april 2019, volume 9, issue 1 of which i am the editorinchief. It is a design model from which many different block ciphers are derived. In part 1, we describe feistel ciphers and their variants. He and a colleague, don coppersmith, published a cipher called lucifer in 1973 that was the first public example of a cipher using a feistel structure.
Foreword by whitfield diffie preface about the author. Cryptography provides a solution to this problem, but it has spawned a heated policy debate. In cryptography, a feistel cipher is a symmetric structure used in the construction of block ciphers, named after the germanborn physicist and cryptographer horst feistel who did pioneering research while working for ibm usa. Data encryption standard des most widely used block cipher in world adopted in 1977 by nbs now nist. Adolf hitler declares universal military service in 1935. This was a block cipher developed by the ibm cryptography researcher horst feistel in the early 70s.
It consists of a number of rounds where each round contains bitshuf. Feistel ciphers are widely used in cryptography in order to obtain pseudorandom permutations and secretkey block ciphers. In the 1960s, though, most of the cryptography research was conducted by governments, but ibm spotted a commercial. The shannon structure shows the implementation of confusion and diffusion alternately. We describe feistel s successful escape from nazi germany, his university training in physics in zurich and in boston, and the career change to cryptography. In the 1970s, horst feistel developed a family of ciphers, the feistel ciphers, while working at ibms watson research. Digital encryption standard des is one the major example of feistel block cipher. Horst feistel january 30, 1915 november 14, 1990 was a germanamerican cryptographer who worked on the design of ciphers at ibm, initiating research that culminated in the development of the data encryption standard des in the 1970s.
The group created an encryption method, named lucifer, to protect the data for a cashdispensing system that ibm had developed for lloyds bank in the united kingdom. Feistel cipher is not a specific scheme of block cipher. Feistel ciphers in east germany in the communist era. So now that we understand what block ciphers are, lets look at a classic example called the data encryption standard. This section and the next two subsections introduce this structure.
Some government agencies want to restrict the use of data encryption. Symmetric key cryptography is the oldest type whereas asymmetric cryptography is only being used publicly since the late 1970s1. Avalanche effect simple english wikipedia, the free. Encryption in production, needs to be elegant and simple. The round of a feistel cipher uses the product of two involutions a function g is called an involution if it is its own inverse. It is previously predominant algorithm for the encryption of a electronic data. Lucifer was the predecessor of the data encryption standard des, and both are built upon the same design. Dataseal demonstration cipher demon lucifer 1973 nbs now nist held a public competition, lucifer won, renamed des data encryption standard controversy collaboration with nsa, key size, secrecy behind design of sboxes. This is a simple 128bit block cipher, reversibly changing a 32bit word of the state at each of 4 steps shown. The data encryption standard block ciphers coursera. One researcher who worked on designing practical block cipher is horst feistel. Cryptography and computer privacy feistel, horst on.