The following outline is provided as an overview of and topical guide to cryptography:

Cryptography Cryptography, or cryptology (from "hidden, secret"; and ''graphein'', "to write", or ''-logy, -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of Adversary (cryptography), ...

(or cryptology) – practice and study of hiding

information Information is an Abstraction, abstract concept that refers to something which has the power Communication, to inform. At the most fundamental level, it pertains to the Interpretation (philosophy), interpretation (perhaps Interpretation (log ...

. Modern cryptography intersects the disciplines of

mathematics Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...

computer science Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, ...

, and

engineering Engineering is the practice of using natural science, mathematics, and the engineering design process to Problem solving#Engineering, solve problems within technology, increase efficiency and productivity, and improve Systems engineering, s ...

. Applications of cryptography include ATM cards, computer passwords, and

electronic commerce E-commerce (electronic commerce) refers to Commerce, commercial activities including the electronic buying or selling Goods and services, products and services which are conducted on online platforms or over the Internet. E-commerce draws on tec ...

Essence of cryptography

Cryptographer Cryptography, or cryptology (from "hidden, secret"; and ''graphein'', "to write", or '' -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More gen ...

Encryption In Cryptography law, cryptography, encryption (more specifically, Code, encoding) is the process of transforming information in a way that, ideally, only authorized parties can decode. This process converts the original representation of the inf ...

decryption In cryptography, encryption (more specifically, encoding) is the process of transforming information in a way that, ideally, only authorized parties can decode. This process converts the original representation of the information, known as plai ...

Cryptographic key A key in cryptography is a piece of information, usually a string of numbers or letters that are stored in a file, which, when processed through a cryptographic algorithm In mathematics and computer science, an algorithm () is a finite sequenc ...

Cipher 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 i ...

Ciphertext In cryptography, ciphertext or cyphertext is the result of encryption performed on plaintext using an algorithm, called a cipher. Ciphertext is also known as encrypted or encoded information because it contains a form of the original plaintext ...

Plaintext In cryptography, plaintext usually means unencrypted information pending input into cryptographic algorithms, usually encryption algorithms. This usually refers to data that is transmitted or stored unencrypted. Overview With the advent of comp ...

Code In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communicati ...

Tabula recta In cryptography, the ''tabula recta'' (from Latin language, Latin ''wikt:tabula#Latin, tabula wikt:rectus#Latin, rēcta'') is a square table of alphabets, each row of which is made by shifting the previous one to the left. The term was invented ...

Alice and Bob Alice and Bob are fictional characters commonly used as placeholders in discussions about cryptography, cryptographic systems and Cryptographic protocol, protocols, and in other science and engineering literature where there are several partici ...

Uses of cryptographic techniques

Commitment scheme A commitment scheme is a cryptographic primitive that allows one to commit to a chosen value (or chosen statement) while keeping it hidden to others, with the ability to reveal the committed value later.Oded Goldreich (2001). Foundations of Crypt ...

s *

Secure multiparty computation Secure multi-party computation (also known as secure computation, multi-party computation (MPC) or privacy-preserving computation) is a subfield of cryptography with the goal of creating methods for parties to jointly compute a function over their ...

Electronic voting Electronic voting is voting that uses electronic means to either aid or handle casting and counting ballots including voting time. Depending on the particular implementation, e-voting may use standalone '' electronic voting machines'' (also ...

Authentication Authentication (from ''authentikos'', "real, genuine", from αὐθέντης ''authentes'', "author") is the act of proving an Logical assertion, assertion, such as the Digital identity, identity of a computer system user. In contrast with iden ...

* Digital signatures *

Crypto system In cryptography, a cryptosystem is a suite of cryptographic algorithms needed to implement a particular security service, such as confidentiality (encryption). Typically, a cryptosystem consists of three algorithms: one for key generation, one fo ...

s *

Dining cryptographers problem In cryptography, the dining cryptographers problem studies how to perform a secure multi-party computation of the boolean-XOR function. David Chaum first proposed this problem in the early 1980s and used it as an illustrative example to show that i ...

Anonymous remailer An anonymous remailer is a server that receives messages with embedded instructions on where to send them next, and that forwards them without revealing where they originally came from. There are cypherpunk anonymous remailers, mixmaster anony ...

Pseudonymity A pseudonym (; ) or alias () is a fictitious name that a person assumes for a particular purpose, which differs from their original or true meaning (orthonym). This also differs from a new name that entirely or legally replaces an individual's ow ...

Onion routing Onion routing is a technique for anonymous communication over a computer network. In an onion network, messages are encapsulated in layers of encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series o ...

Digital currency Digital currency (digital money, electronic money or electronic currency) is any currency, money, or money-like asset that is primarily managed, stored or exchanged on digital computer systems, especially over the internet. Types of digital cu ...

Secret sharing Secret sharing (also called secret splitting) refers to methods for distributing a secrecy, secret among a group, in such a way that no individual holds any intelligible information about the secret, but when a sufficient number of individuals c ...

Indistinguishability obfuscation In cryptography, indistinguishability obfuscation (abbreviated IO or iO) is a type of software obfuscation with the defining property that obfuscating any two programs that compute the same mathematical function results in programs that cannot be ...

Branches of cryptography

Multivariate cryptography Multivariate cryptography is the generic term for asymmetric cryptographic primitives based on multivariate polynomials over a finite field F. In certain cases, those polynomials could be defined over both a ground and an extension field. If t ...

Post-quantum cryptography Post-quantum cryptography (PQC), sometimes referred to as quantum-proof, quantum-safe, or quantum-resistant, is the development of cryptographic algorithms (usually public-key algorithms) that are currently thought to be secure against a crypt ...

Quantum cryptography Quantum cryptography is the science of exploiting quantum mechanical properties to perform cryptographic tasks. The best known example of quantum cryptography is quantum key distribution, which offers an information-theoretically secure soluti ...

Steganography Steganography ( ) is the practice of representing information within another message or physical object, in such a manner that the presence of the concealed information would not be evident to an unsuspecting person's examination. In computing/ ...

* Visual cryptography * Chaotic cryptology

History of cryptography

* Japanese cryptology from the 1500s to Meiji * World War I cryptography * World War II cryptography ** Reservehandverfahren ** Venona project **

Ultra Ultra may refer to: Science and technology * Ultra (cryptography), the codename for cryptographic intelligence obtained from signal traffic in World War II * Adobe Ultra, a vector-keying application * Sun Ultra series, a brand of computer work ...

Ciphers

Classical

Substitution

* Monoalphabetic substitution **

Caesar cipher In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code, or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in t ...

***

ROT13 ROT13 is a simple letter substitution cipher that replaces a letter with the 13th letter after it in the Latin alphabet. ROT13 is a special case of the Caesar cipher which was developed in ancient Rome, used by Julius Caesar in the 1st centur ...

** Affine cipher ** Atbash cipher ** Keyword cipher * Polyalphabetic substitution **

Vigenère cipher The Vigenère cipher () is a method of encryption, encrypting alphabetic text where each letter of the plaintext is encoded with a different Caesar cipher, whose increment is determined by the corresponding letter of another text, the key (crypt ...

Autokey cipher An autokey cipher (also known as the autoclave cipher) is a cipher that incorporates the message (the plaintext) into the key. The key is generated from the message in some automated fashion, sometimes by selecting certain letters from the text o ...

Homophonic substitution cipher In cryptography, a substitution cipher is a method of encrypting in which units of plaintext are replaced with the ciphertext, in a defined manner, with the help of a key; the "units" may be single letters (the most common), pairs of letters, t ...

* Polygraphic substitution ** Playfair cipher **

Hill cipher In classical cryptography, the Hill cipher is a polygraphic substitution cipher based on linear algebra. Invented by Lester S. Hill in 1929, it was the first polygraphic cipher in which it was practical (though barely) to operate on more than t ...

Transposition

Scytale In cryptography, a scytale (; also transliterated skytale, ''skutálē'' "baton, cylinder", also ''skútalon'') is a tool used to perform a transposition cipher, consisting of a cylinder with a strip of parchment wound around it on which is wr ...

* Grille * Permutation cipher * VIC cipher – complex hand cypher used by at least one Soviet spy in the early 1950s; it proved quite secure for the time

Modern symmetric-key algorithms

Stream ciphers A stream cipher is a symmetric key algorithm, symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream (keystream). In a stream cipher, each plaintext numerical digit, digit is encrypted one at a time with ...

* A5/1 & A5/2 – ciphers specified for the

GSM The Global System for Mobile Communications (GSM) is a family of standards to describe the protocols for second-generation (2G) digital cellular networks, as used by mobile devices such as mobile phones and Mobile broadband modem, mobile broadba ...

cellular telephone standard * BMGL *

Chameleon Chameleons or chamaeleons (Family (biology), family Chamaeleonidae) are a distinctive and highly specialized clade of Old World lizards with 200 species described as of June 2015. The members of this Family (biology), family are best known for ...

FISH A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

– by Siemens AG * WWII 'Fish' cyphers **

Geheimfernschreiber The Siemens & Halske T52, also known as the Geheimschreiber ("secret teleprinter"), or ''Schlüsselfernschreibmaschine'' (SFM), was a World War II German cipher machine and teleprinter produced by the electrical engineering firm Siemens & Halske. ...

– WWII mechanical onetime pad by

Siemens AG Siemens AG ( ) is a German multinational technology conglomerate. It is focused on industrial automation, building automation, rail transport and health technology. Siemens is the largest engineering company in Europe, and holds the posit ...

, called

STURGEON Sturgeon (from Old English ultimately from Proto-Indo-European language, Proto-Indo-European *''str̥(Hx)yón''-) is the common name for the 27 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the ...

Bletchley Park Bletchley Park is an English country house and Bletchley Park estate, estate in Bletchley, Milton Keynes (Buckinghamshire), that became the principal centre of Allies of World War II, Allied World War II cryptography, code-breaking during the S ...

** Pike – improvement on FISH by Ross Anderson ** Schlusselzusatz – WWII mechanical onetime pad by

Lorenz Lorenz is an originally German name derived from the Roman surname Laurentius, which means "from Laurentum". Given name People with the given name Lorenz include: * Prince Lorenz of Belgium (born 1955), member of the Belgian royal family by h ...

, called ''tunny'' by

HELIX A helix (; ) is a shape like a cylindrical coil spring or the thread of a machine screw. It is a type of smooth space curve with tangent lines at a constant angle to a fixed axis. Helices are important in biology, as the DNA molecule is for ...

ISAAC Isaac ( ; ; ; ; ; ) is one of the three patriarchs (Bible), patriarchs of the Israelites and an important figure in the Abrahamic religions, including Judaism, Christianity, Islam, and the Baháʼí Faith. Isaac first appears in the Torah, in wh ...

– intended as a PRNG *

Leviathan Leviathan ( ; ; ) is a sea serpent demon noted in theology and mythology. It is referenced in several books of the Hebrew Bible, including Psalms, the Book of Job, the Book of Isaiah, and the pseudepigraphical Book of Enoch. Leviathan is of ...

LILI-128 LILI-128 is an LFSR based synchronous stream cipher with a 128-bit key. On 13 November 2000, LILI-128 was presented at the NESSIE workshop. It is designed to be simple to implement in both software and hardware. In 2007, LILI-128 was totally br ...

MUGI In cryptography, MUGI is a pseudorandom number generator (PRNG) designed for use as a stream cipher. It was among the cryptographic techniques recommended for Japanese government use by CRYPTREC in 2003, however, has been dropped to "candidate" ...

–

CRYPTREC CRYPTREC is the Cryptography Research and Evaluation Committees set up by the Japanese Government to evaluate and recommend cryptographic techniques for government and industrial use. It is comparable in many respects to the European Union's NESSI ...

recommendation *

MULTI-S01 In cryptography, MULTI-S01 (pronounced ''multi-ess-zero-one''), is an encryption algorithm based on a pseudorandom number generator (PRNG). MULTI-S01 is an encryption scheme preserving both confidentiality and data integrity. The scheme defines a pa ...

recommendation *

One-time pad The one-time pad (OTP) is an encryption technique that cannot be Cryptanalysis, cracked in cryptography. It requires the use of a single-use pre-shared key that is larger than or equal to the size of the message being sent. In this technique, ...

– Vernam and Mauborgne, patented 1919; an extreme stream cypher *

Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

RC4 In cryptography, RC4 (Rivest Cipher 4, also known as ARC4 or ARCFOUR, meaning Alleged RC4, see below) is a stream cipher. While it is remarkable for its simplicity and speed in software, multiple vulnerabilities have been discovered in RC4, ren ...

(ARCFOUR) – one of a series by Professor Ron Rivest of

MIT The Massachusetts Institute of Technology (MIT) is a private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of modern technology and sc ...

;

recommended limited to 128-bit key **

CipherSaber CipherSaber is a simple symmetric encryption Protocol (computing), protocol based on the RC4 stream cipher. Its goals are both technical and politics, political: it gives reasonably strong protection of message confidentiality, yet it's designed ...

– (

variant with 10 byte random IV, easy to implement *

Salsa20 Salsa20 and the closely related ChaCha are stream ciphers developed by Daniel J. Bernstein. Salsa20, the original cipher, was designed in 2005, then later submitted to the eSTREAM European Union cryptographic validation process by Bernstein. Ch ...

– an

eSTREAM eSTREAM is a project to "identify new stream ciphers suitable for widespread adoption", organised by the EU ECRYPT network. It was set up as a result of the failure of all six stream ciphers submitted to the NESSIE project. The call for primiti ...

recommended cipher **

ChaCha20 Salsa20 and the closely related ChaCha are stream ciphers developed by Daniel J. Bernstein. Salsa20, the original cipher, was designed in 2005, then later submitted to the eSTREAM European Union cryptographic validation process by Bernstein. Ch ...

– A Salsa20 variant. *

SEAL Seal may refer to any of the following: Common uses * Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly: ** Earless seal, also called "true seal" ** Fur seal ** Eared seal * Seal ( ...

SNOW Snow consists of individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water througho ...

SOBER Sober usually refers to sobriety, the state of not having any measurable levels or effects from alcohol or drugs. Sober may also refer to: Music * Sôber, Spanish rock band Songs * "Sober" (Bad Wolves song), from the 2019 album ''Nation'' * " ...

** SOBER-t16 ** SOBER-t32 * WAKE

Block ciphers In cryptography, a block cipher is a deterministic algorithm that operates on fixed-length groups of bits, called ''blocks''. Block ciphers are the elementary building blocks of many cryptographic protocols. They are ubiquitous in the storage a ...

Product cipher In cryptography, a product cipher combines two or more transformations in a manner intending that the resulting cipher is more secure than the individual components to make it resistant to cryptanalysis.Handbook of Applied Cryptography by Alfred J. ...

Feistel cipher 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 resear ...

– pattern by

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

Advanced Encryption Standard The Advanced Encryption Standard (AES), also known by its original name Rijndael (), is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) in 2001. AES is a variant ...

(Rijndael) – 128-bit block;

NIST The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical s ...

selection for the AES, FIPS 197; Created 2001—by

Joan Daemen Joan Daemen (; born 1965) is a Belgians, Belgian cryptographer who is currently professor of digital security (symmetric encryption) at Radboud University. He co-designed with Vincent Rijmen the Rijndael cipher, which was selected as the Advance ...

and

Vincent Rijmen Vincent Rijmen (; born 16 October 1970) is a Belgium, Belgian cryptographer and one of the two designers of the Rijndael, the Advanced Encryption Standard. Rijmen is also the co-designer of the WHIRLPOOL cryptographic hash function, and the block ...

;

NESSIE NESSIE (New European Schemes for Signatures, Integrity and Encryption) was a European research project funded from 2000 to 2003 to identify secure cryptographic primitives. The project was comparable to the NIST AES process and the Japanese Go ...

selection;

recommendation. *

Anubis Anubis (; ), also known as Inpu, Inpw, Jnpw, or Anpu in Ancient Egyptian (), is the god of funerary rites, protector of graves, and guide to the underworld in ancient Egyptian religion, usually depicted as a canine or a man with a canine hea ...

– 128-bit block *

BEAR Bears are carnivoran mammals of the family (biology), family Ursidae (). They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats ...

– built from a stream cypher and hash function, by Ross Anderson *

Blowfish Tetraodontidae is a family of marine and freshwater fish in the order Tetraodontiformes. The family includes many familiar species variously called pufferfish, puffers, balloonfish, blowfish, blowers, blowies, bubblefish, globefish, swellfish, ...

– 64-bit block; by

Bruce Schneier Bruce Schneier (; born January 15, 1963) is an American cryptographer, computer security professional, privacy specialist, and writer. Schneier is an Adjunct Lecturer in Public Policy at the Harvard Kennedy School and a Fellow at the Berkman ...

''et al.'' *

Camellia ''Camellia'' (pronounced or ) is a genus of flowering plants in the family Theaceae. They are found in tropical and subtropical areas in East Asia, eastern and South Asia, southern Asia, from the Himalayas east to Japan and Indonesia. There are ...

– 128-bit block;

selection (NTT & Mitsubishi Electric);

recommendation * CAST-128 ( CAST5) – 64-bit block; one of a series of algorithms by

Carlisle Adams Carlisle M. Adams is a Canadian cryptographer and computer security researcher. Formerly senior cryptographer at Entrust, he is currently a professor at the University of Ottawa. His notable work includes the design (with Stafford Tavares) of the ...

and

Stafford Tavares Stafford Emanuel Tavares is a Canadian cryptographer, professor emeritus at Queen's University. His notable work includes the design (with Carlisle Adams) of the block ciphers CAST-128 and CAST-256. He also helped organize the first Selected A ...

, insistent that the name is not due to their initials **

CAST-256 In cryptography, CAST-256 (or CAST6) is a symmetric-key block cipher published in June 1998. It was submitted as a candidate for the Advanced Encryption Standard (AES); however, it was not among the five AES finalists. It is an extension of an ...

(

CAST6 In cryptography, CAST-256 (or CAST6) is a symmetric-key block cipher published in June 1998. It was submitted as a candidate for the Advanced Encryption Standard (AES); however, it was not among the five AES finalists. It is an extension of an ...

) – 128-bit block; the successor to CAST-128 and a candidate for the AES competition *

CIPHERUNICORN-A In cryptography, CIPHERUNICORN-A is a block cipher created by NEC in 2000. It was among the cryptographic techniques recommended for Japanese government use by CRYPTREC in 2003. However, it has been dropped to "candidate" level by the CRYPTREC re ...

– 128-bit block;

recommendation *

CIPHERUNICORN-E In cryptography, CIPHERUNICORN-E is a block cipher created by NEC in 1998. It was among the cryptographic techniques recommended for Japanese government use by CRYPTREC in 2003. However, it has been dropped to "candidate" level by the CRYPTREC rev ...

– 64-bit block;

recommendation (limited) * CMEA – cipher used in US cellphones, found to have weaknesses. * CS-Cipher – 64-bit block *

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 cryp ...

(DES) – 64-bit block; FIPS 46-3, 1976 *

DEAL In cryptography, DEAL (Data Encryption Algorithm with Larger blocks) is a symmetric block cipher derived from the Data Encryption Standard (DES). Its design was presented by Lars Knudsen at the SAC conference in 1997, and submitted as a proposa ...

– an AES candidate derived from DES * DES-X – a variant of DES to increase the key size. *

FEAL In cryptography, FEAL (the Fast data Encipherment Algorithm) is a block cipher proposed as an alternative to the Data Encryption Standard (DES), and designed to be much faster in software. The Feistel based algorithm was first published in 1987 ...

* GDES – a DES variant designed to speed up encryption * Grand Cru – 128-bit block *

Hierocrypt-3 In cryptography, Hierocrypt-L1 and Hierocrypt-3 are block ciphers created by Toshiba in 2000. They were submitted to the NESSIE project, but were not selected. Both algorithms were among the cryptographic techniques recommended for Japanese gover ...

– 128-bit block;

recommendation * Hierocrypt-L1 – 64-bit block;

recommendation (limited) * IDEA NXT – project name FOX, 64-bit and 128-bit block family; Mediacrypt (Switzerland); by

Pascal Junod Pascal, Pascal's or PASCAL may refer to: People and fictional characters * Pascal (given name), including a list of people with the name * Pascal (surname), including a list of people and fictional characters with the name ** Blaise Pascal, Frenc ...

Serge Vaudenay Serge Vaudenay (born 5 April 1968) is a French cryptographer and professor, director of the Communications Systems Section at the École Polytechnique Fédérale de Lausanne Serge Vaudenay entered the École Normale Supérieure in Paris as a ''n ...

of Swiss Institute of Technology Lausanne *

International Data Encryption Algorithm In cryptography, the International Data Encryption Algorithm (IDEA), originally called Improved Proposed Encryption Standard (IPES), is a Symmetric-key algorithm, symmetric-key block cipher designed by James Massey of ETH Zurich and Xuejia Lai an ...

(IDEA) – 64-bit block;

James Massey James Lee Massey (February 11, 1934 – June 16, 2013) was an American information theorist and cryptographer, Professor Emeritus of Digital Technology at ETH Zurich. His notable work includes the application of the Berlekamp–Massey algorithm t ...

& X Lai of

ETH Eth ( , uppercase: ⟨Ð⟩, lowercase: ⟨ð⟩; also spelled edh or eð), known as in Old English, is a letter used in Old English, Middle English, Icelandic, Faroese (in which it is called ), and Elfdalian. It was also used in Sca ...

Zurich *

Iraqi Block Cipher In cryptography, the Iraqi block cipher was a block cipher published in C source code form by anonymous FTP upload around July 1999, and widely distributed on Usenet. It is a five round unbalanced Feistel cipher operating on a 256 bit block with ...

(IBC) *

KASUMI Kasumi may refer to: Places * Kasumi, Hyōgo (香住), a former town in Hyōgo Prefecture, Japan * Kasumigaseki Kasumigaseki (霞が関, 霞ヶ関 or 霞ケ関) is a district in Chiyoda, Tokyo, Chiyoda, Tokyo. Most government ministries are loca ...

– 64-bit block; based on

MISTY1 In cryptography, MISTY1 (or MISTY-1) is a block cipher designed in 1995 by Mitsuru Matsui and others for Mitsubishi Electric. MISTY1 is one of the selected algorithms in the European NESSIE project, and has been among the cryptographic techniq ...

, adopted for next generation

W-CDMA The Universal Mobile Telecommunications System (UMTS) is a 3G mobile cellular system for networks based on the GSM standard. UMTS uses wideband code-division multiple access (W-CDMA) radio access technology to offer greater spectral efficiency ...

cellular phone A mobile phone or cell phone is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones ( landline phones). This radi ...

security *

KHAZAD In cryptography, KHAZAD is a block cipher designed by Paulo S. L. M. Barreto together with Vincent Rijmen, one of the designers of the Advanced Encryption Standard (Rijndael). KHAZAD is named after Khazad-dûm, the fictional dwarven realm in the ...

– 64-bit block designed by Barretto and Rijmen *

Khufu and Khafre In cryptography, Khufu and Khafre are two block ciphers designed by Ralph Merkle in 1989 while working at Xerox's Palo Alto Research Center. Along with Snefru, a cryptographic hash function, the ciphers were named after the Egyptian Pharaohs Kh ...

– 64-bit block ciphers *

Kuznyechik Kuznyechik (, literally "grasshopper") is a symmetric block cipher. It has a block size of 128 bits and key length of 256 bits. It is defined in the National Standard of the Russian Federation GOST R 34.12-2015 and also in RFC 7801. The name of ...

– Russian 128-bit block cipher, defined in GOST R 34.12-2015 and RFC 7801. *

LION The lion (''Panthera leo'') is a large Felidae, cat of the genus ''Panthera'', native to Sub-Saharan Africa and India. It has a muscular, broad-chested body (biology), body; a short, rounded head; round ears; and a dark, hairy tuft at the ...

– block cypher built from stream cypher and hash function, by Ross Anderson * LOKI89/91 – 64-bit block ciphers *

LOKI97 In cryptography, LOKI97 is a block cipher which was a candidate in the Advanced Encryption Standard competition. It is a member of the LOKI family of ciphers, with earlier instances being LOKI89 and LOKI91. LOKI97 was designed by Lawrie Brown ...

– 128-bit block cipher, AES candidate *

Lucifer The most common meaning for Lucifer in English is as a name for the Devil in Christian theology. He appeared in the King James Version of the Bible in Isaiah and before that in the Vulgate (the late-4th-century Latin translation of the Bib ...

– by Tuchman ''et al.'' of

IBM International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...

, early 1970s; modified by

NSA The National Security Agency (NSA) is an intelligence agency of the United States Department of Defense, under the authority of the director of national intelligence (DNI). The NSA is responsible for global monitoring, collection, and proces ...

/National Institute of Standards and Technology, NBS and released as DES * MAGENTA – AES candidate * Mars (cipher), Mars – AES finalist, by Don Coppersmith et al. *

–

selection 64-bit block; Mitsubishi Electric (Japan);

recommendation (limited) * MISTY2 – 128-bit block: Mitsubishi Electric (Japan) * Nimbus (cipher), Nimbus – 64-bit block * NOEKEON – 128-bit block * NUSH – variable block length (64-256-bit) * Q (cipher), Q – 128-bit block * RC2 – 64-bit block, variable key length ** RC6 – variable block length; AES finalist, by Ron Rivest ''et al.'' ** RC5 – Ron Rivest * Secure and Fast Encryption Routine, SAFER – variable block length * SC2000 – 128-bit block;

recommendation * Serpent (cipher), Serpent – 128-bit block; AES finalist by Ross Anderson, Eli Biham, Lars Knudsen * SHACAL-1 – 160-bit block * SHACAL-2 – 256-bit block cypher;

selection Gemplus (France) * Shark (cipher), Shark – grandfather of Rijndael/Advanced Encryption Standard, AES, by Daemen and Rijmen ** Square (cipher), Square – father of Rijndael/Advanced Encryption Standard, AES, by Daemen and Rijmen * Tiny Encryption Algorithm, TEA – by David Wheeler (computer scientist), David Wheeler & Roger Needham * Triple DES – by Walter Tuchman, leader of the

design team—not all triple uses of DES increase security, Tuchman's does;

recommendation (limited), only when used as in FIPS Pub 46-3 * Twofish – 128-bit block; AES finalist by

''et al.'' * XTEA – by David Wheeler (computer scientist), David Wheeler & Roger Needham * 3-Way – 96-bit block by

* Polyalphabetic substitution machine cyphers ** Enigma (machine), Enigma – WWII German rotor cypher machine—many variants, any user networks for most of the variants ** Purple code, Purple – highest security WWII Japanese Foreign Office cypher machine; by Japanese Navy Captain ** SIGABA – WWII US cypher machine by William Friedman, Frank Rowlett ''et al.'' ** TypeX – WWII UK cypher machine *Hybrid code/cypher combinations ** JN-25 – WWII Japanese Navy superencyphered code; many variants ** Naval Cypher 3 – superencrypted code used by the Royal Navy in the 1930s and into WWII

Modern asymmetric-key algorithms

Asymmetric key algorithm

* ACE-KEM –

selection asymmetric encryption scheme; IBM Zurich Research ** ACE Encrypt * Chor-Rivest * Diffie-Hellman – key agreement;

recommendation * El Gamal – discrete logarithm * Elliptic curve cryptography – (discrete logarithm variant) * PSEC-KEM –

selection asymmetric encryption scheme; NTT (Japan);

recommendation only in DEM construction w/SEC1 parameters ** ECIES – ''Elliptic Curve Integrated Encryption System'', Certicom Corporation ** ECIES-KEM ** ECDH – ''Elliptic Curve Diffie-Hellman key agreement'',

recommendation * Efficient Probabilistic Public-Key Encryption Scheme, EPOC * Kyber * Merkle–Hellman knapsack cryptosystem – knapsack scheme * McEliece cryptosystem * Niederreiter cryptosystem * NTRUEncrypt * RSA (algorithm), RSA – factoring ** RSA-KEM –

selection asymmetric encryption scheme; ISO/IEC 18033-2 draft ** RSA-OAEP –

recommendation * Rabin cryptosystem – factoring ** Rabin-SAEP ** HIME(R) * Paillier cryptosystem * Threshold cryptosystem * XTR

Keys

Key authentication

* Public key infrastructure ** X.509 ** OpenPGP * Public key certificate ** Certificate authority ** Certificate revocation * ID-based cryptography * Certificate-based encryption * Secure key issuing cryptography * Certificateless cryptography * Merkle tree

Transport/exchange

* Diffie–Hellman * Man-in-the-middle attack * Needham–Schroeder * Offline private key * Otway–Rees * Trusted paper key * Wide Mouth Frog

Weak keys

* Brute force attack * Dictionary attack * Related key attack * Key derivation function * Key strengthening * Password * Password-authenticated key agreement * Passphrase * Salt (cryptography), Salt * Factorization

Cryptographic hash functions

* Message authentication code * Keyed-hash message authentication code ** Encrypted CBC-MAC (EMAC) –

selection MAC ** HMAC –

selection MAC; ISO/IEC 9797-1, FIPS PUB 113 and IETF Request for Comments, RFC ** TTMAC – (Two-Track-MAC) NESSIE selection MAC; K.U.Leuven (Belgium) & debis AG (Germany) ** UMAC (cryptography), UMAC –

selection MAC; Intel, UNevada Reno, IBM, Technion, & UC Davis ** Oblivious Pseudorandom Function * MD5 – one of a series of message digest algorithms by Prof Ron Rivest of MIT; 128-bit digest * SHA-1 – developed at

160-bit digest, an FIPS standard; the first released version was defective and replaced by this; NIST/NSA have released several variants with longer 'digest' lengths;

recommendation (limited) ** SHA-256 –

selection hash function, FIPS 180-2, 256-bit digest;

recommendation ** SHA-384 –

selection hash function, FIPS 180-2, 384-bit digest;

recommendation ** SHA-512 –

selection hash function, FIPS 180-2, 512-bit digest;

recommendation * SHA-3 – originally known as Keccak; was the winner of the NIST hash function competition using sponge function. * Streebog – Russian algorithm created to replace an obsolete GOST hash function defined in obsolete standard GOST R 34.11-94. * RIPEMD-160 – developed in Europe for the RIPE project, 160-bit digest;

recommendation (limited) * RTR0 – one of Retter series; developed by Maciej A. Czyzewski; 160-bit digest * Tiger (hash function), Tiger – by Ross Anderson ''et al.'' * Snefru (cryptography), Snefru – NIST hash function competition * Whirlpool (algorithm), Whirlpool –

selection hash function, Scopus Tecnologia S.A. (Brazil) & K.U.Leuven (Belgium)

Cryptanalysis

Classical

* Frequency analysis * Contact analysis (cryptanalysis), Contact analysis * Index of coincidence * Kasiski examination

Modern

* Symmetric algorithms ** Boomerang attack ** Brute force attack ** Davies' attack ** Differential cryptanalysis ** Impossible differential cryptanalysis ** Integral cryptanalysis ** Linear cryptanalysis ** Meet-in-the-middle attack ** Mod-n cryptanalysis ** Related-key attack ** Slide attack ** XSL attack * Hash functions: ** Birthday attack * Attack models **Chosen-ciphertext attack, Chosen-ciphertext **Chosen-plaintext attack, Chosen-plaintext **Ciphertext-only attack, Ciphertext-only **Known-plaintext attack, Known-plaintext * Side channel attacks ** Power analysis ** Timing attack ** Cold boot attack ** Differential fault analysis * Network attacks ** Man-in-the-middle attack ** Replay attack * External attacks ** Black-bag cryptanalysis ** Rubber-hose cryptanalysis

Robustness properties

* Provable security * Random oracle, Random oracle model * Ciphertext indistinguishability * Semantic security * Malleability (cryptography), Malleability * Forward secrecy * Forward anonymity * Freshness (cryptography), Freshness *

Undeciphered historical codes and ciphers

* Beale ciphers * Chaocipher * D'Agapeyeff cipher * Dorabella cipher * Rongorongo * Shugborough inscription * Voynich manuscript

Organizations and selection projects

Cryptography standards

* Federal Information Processing Standards (FIPS) Publication Program – run by

to produce standards in many areas to guide operations of the US Federal government; many FIPS publications are ongoing and related to cryptography * American National Standards Institute (ANSI) – standardization process that produces many standards in many areas; some are cryptography related, ongoing) * International Organization for Standardization (ISO) – standardization process produces many standards in many areas; some are cryptography related, ongoing * Institute of Electrical and Electronics Engineers (IEEE) – standardization process produces many standards in many areas; some are cryptography related, ongoing * Internet Engineering Task Force (IETF) – standardization process that produces many standards called Request for Comments, RFCs) in many areas; some are cryptography related, ongoing)

General cryptographic

* National Security Agency (NSA) – internal evaluation/selections, charged with assisting NIST in its cryptographic responsibilities * Government Communications Headquarters (GCHQ) – internal evaluation/selections, a division is charged with developing and recommending cryptographic standards for the UK government * Defence Signals Directorate (DSD) – Australian SIGINT agency, part of ECHELON * Communications Security Establishment (CSE) – Canadian intelligence agency

Open efforts

(DES) – NIST, NBS selection process, ended 1976 * RIPE – division of the RACE project sponsored by the European Union, ended mid-1980s *

(AES) – a "break-off" competition sponsored by

, ended in 2001 *

Project – an evaluation/selection program sponsored by the European Union, ended in 2002 *

– program funded by ECRYPT; motivated by the failure of all of the stream ciphers submitted to

, ended in 2008 *

– evaluation/recommendation program sponsored by the Japanese government; draft recommendations published 2003 * CrypTool – an e-learning freeware programme in English and German— exhaustive educational tool about cryptography and cryptanalysis

Influential cryptographers

List of cryptographers

Legal issues

* AACS encryption key controversy * Free speech ** ''Bernstein v. United States'' - Daniel J. Bernstein's challenge to the restrictions on the export of cryptography from the United States. ** ''Junger v. Daley'' ** DeCSS ** Phil Zimmermann#Arms Export Control Act investigation, Phil Zimmermann - Arms Export Control Act investigation regarding the Pretty Good Privacy, PGP software. * Export of cryptography * Key escrow and Clipper Chip * Digital Millennium Copyright Act * Digital rights management (DRM) * Patents ** RSA (algorithm), RSA – now public domain ** David Chaum – and digital cash * Cryptography and law enforcement ** Telephone tapping, Telephone wiretapping ** Espionage * Cryptography laws in different nations ** Official Secrets Act – United Kingdom, India, Ireland, Malaysia, and formerly New Zealand ** Regulation of Investigatory Powers Act 2000 – United Kingdom

Academic and professional publications

* Journal of Cryptology * Encyclopedia of Cryptography and Security * Cryptologia – quarterly journal focusing on historical aspects * Communication Theory of Secrecy Systems – cryptography from the viewpoint of information theory * International Association for Cryptologic Research
website

Allied sciences

* Security engineering

References

{{Outline footer Outlines of sciences, Cryptography Outlines, Cryptography Cryptography lists and comparisons, *

Essence of cryptography

Uses of cryptographic techniques

Branches of cryptography

History of cryptography

Ciphers

Classical

Substitution

Transposition

Modern symmetric-key algorithms

Stream ciphers A stream cipher is a symmetric key algorithm, symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream (keystream). In a stream cipher, each plaintext numerical digit, digit is encrypted one at a time with ...

Block ciphers In cryptography, a block cipher is a deterministic algorithm that operates on fixed-length groups of bits, called ''blocks''. Block ciphers are the elementary building blocks of many cryptographic protocols. They are ubiquitous in the storage a ...

Modern asymmetric-key algorithms

Asymmetric key algorithm

Keys

Key authentication

Transport/exchange

Weak keys

Cryptographic hash functions

Cryptanalysis

Classical

Modern

Robustness properties

Undeciphered historical codes and ciphers

Organizations and selection projects

Cryptography standards

General cryptographic

Open efforts

Influential cryptographers

Legal issues

Academic and professional publications

Allied sciences

See also

References