Outline of cryptography

Essence of cryptography

• Cryptographer
• Encryption/decryption
• Cryptographic key
• Cipher
• Ciphertext
• Plaintext
• Code
• Tabula recta
• Alice and Bob

  Uses of cryptographic techniques

• Commitment schemes
• Secure multiparty computation
• Electronic voting
• Authentication
• Digital signatures
• Crypto systems
• Dining cryptographers problem
• Anonymous remailer
• Pseudonymity
• Onion routing
• Digital currency
• Secret sharing
• Indistinguishability obfuscation

  Branches of cryptography

• Multivariate cryptography
• Post-quantum cryptography
• Quantum cryptography
• Steganography
• Visual cryptography

  History of cryptography

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

  Ciphers

Classical

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• Monoalphabetic substitution
• * Caesar cipher
• ** ROT13
• * Affine cipher
• * Atbash cipher
• * Keyword cipher
• Polyalphabetic substitution
• * Vigenère cipher
• * Autokey cipher
• * Homophonic substitution cipher
• Polygraphic substitution
• * Playfair cipher
• * Hill cipher

  Transposition">Transposition cipher">Transposition

• Scytale
• 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]

• A5/1 & A5/2 - ciphers specified for the GSM cellular telephone standard
• BMGL
• Chameleon
• FISH - by Siemens AG
• WWII 'Fish' cyphers
• * Geheimfernschreiber - WWII mechanical onetime pad by Siemens AG, called STURGEON by Bletchley Park
• * Pike - improvement on FISH by Ross Anderson
• * Schlusselzusatz - WWII mechanical onetime pad by Lorenz, called tunny by Bletchley Park
• HELIX
• ISAAC - intended as a PRNG
• Leviathan
• LILI-128
• MUGI - CRYPTREC recommendation
• MULTI-S01 - CRYPTREC recommendation
• One-time pad - Vernam and Mauborgne, patented 1919; an extreme stream cypher
• Panama
• RC4 - one of a series by Professor Ron Rivest of MIT; CRYPTREC recommended limited to 128-bit key
• * CipherSaber - (RC4 variant with 10 byte random IV, easy to implement
• Salsa20 - an eSTREAM recommended cipher
• * ChaCha20 - A Salsa20 variant.
• SEAL
• SNOW
• SOBER
• * SOBER-t16
• * SOBER-t32
• WAKE

  [Block ciphers]

• Product cipher
• Feistel cipher - pattern by Horst Feistel
• Advanced Encryption Standard - 128-bit block; NIST selection for the AES, FIPS 197; Created 2001—by Joan Daemen and Vincent Rijmen; NESSIE selection; CRYPTREC recommendation.
• Anubis - 128-bit block
• BEAR - built from a stream cypher and hash function, by Ross Anderson
• Blowfish - 64-bit block; by Bruce Schneier et al.
• Camellia - 128-bit block; NESSIE selection ; CRYPTREC recommendation
• CAST-128 - 64-bit block; one of a series of algorithms by Carlisle Adams and Stafford Tavares, insistent that the name is not due to their initials
• * CAST-256 - 128-bit block; the successor to CAST-128 and a candidate for the AES competition
• CIPHERUNICORN-A - 128-bit block; CRYPTREC recommendation
• CIPHERUNICORN-E - 64-bit block; CRYPTREC recommendation
• CMEA - cipher used in US cellphones, found to have weaknesses.
• CS-Cipher - 64-bit block
• Data Encryption Standard - 64-bit block; FIPS 46-3, 1976
• DEAL - an AES candidate derived from DES
• DES-X - a variant of DES to increase the key size.
• FEAL
• GDES - a DES variant designed to speed up encryption
• Grand Cru - 128-bit block
• Hierocrypt-3 - 128-bit block; CRYPTREC recommendation
• Hierocrypt-L1 - 64-bit block; CRYPTREC recommendation
• IDEA NXT - project name FOX, 64-bit and 128-bit block family; Mediacrypt ; by Pascal Junod & Serge Vaudenay of Swiss Institute of Technology Lausanne
• International Data Encryption Algorithm - 64-bit block;James Massey & X Lai of ETH Zurich
• Iraqi Block Cipher
• KASUMI - 64-bit block; based on MISTY1, adopted for next generation W-CDMA cellular phone security
• KHAZAD - 64-bit block designed by Barretto and Rijmen
• Khufu and Khafre - 64-bit block ciphers
• Kuznyechik - Russian 128-bit block cipher, defined in GOST R 34.12-2015 and RFC 7801.
• LION - block cypher built from stream cypher and hash function, by Ross Anderson
• LOKI89/91 - 64-bit block ciphers
• LOKI97 - 128-bit block cipher, AES candidate
• Lucifer - by Tuchman et al. of IBM, early 1970s; modified by NSA/NBS and released as DES
• MAGENTA - AES candidate
• Mars - AES finalist, by Don Coppersmith et al.
• MISTY1 - NESSIE selection 64-bit block; Mitsubishi Electric ; CRYPTREC recommendation
• MISTY2 - 128-bit block: Mitsubishi Electric
• Nimbus - 64-bit block
• NOEKEON - 128-bit block
• NUSH - variable block length
• 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
• SAFER - variable block length
• SC2000 - 128-bit block; CRYPTREC recommendation
• Serpent - 128-bit block; AES finalist by Ross Anderson, Eli Biham, Lars Knudsen
• SHACAL-1 - 160-bit block
• SHACAL-2 - 256-bit block cypher; NESSIE selection Gemplus
• Shark - grandfather of Rijndael/AES, by Daemen and Rijmen
• * Square - father of Rijndael/AES, by Daemen and Rijmen
• TEA - by David Wheeler & Roger Needham
• Triple DES - by Walter Tuchman, leader of the Lucifer design team—not all triple uses of DES increase security, Tuchman's does; CRYPTREC recommendation, only when used as in FIPS Pub 46-3
• Twofish - 128-bit block; AES finalist by Bruce Schneier et al.
• XTEA - by David Wheeler & Roger Needham
• 3-Way - 96-bit block by Joan Daemen
• Polyalphabetic substitution machine cyphers
• * Enigma - WWII German rotor cypher machine—many variants, any user networks for most of the variants
• * 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 - NESSIE selection asymmetric encryption scheme; IBM Zurich Research
• * ACE Encrypt
• Chor-Rivest
• Diffie-Hellman - key agreement; CRYPTREC recommendation
• El Gamal - discrete logarithm
• Elliptic curve cryptography -
• PSEC-KEM - NESSIE selection asymmetric encryption scheme; NTT ; CRYPTREC 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, CRYPTREC recommendation
• EPOC
• Merkle–Hellman knapsack cryptosystem - knapsack scheme
• McEliece cryptosystem
• Niederreiter cryptosystem
• NTRUEncrypt
• RSA - factoring
• * RSA-KEM - NESSIE selection asymmetric encryption scheme; ISO/IEC 18033-2 draft
• * RSA-OAEP - CRYPTREC recommendation
• Rabin cryptosystem - factoring
• * Rabin-SAEP
• * HIME
• Threshold cryptosystem
• XTR

  Keys

[Key authentication]

• Public key infrastructure
• * X.509
• * OpenPGP
• Public key certificate
• * Certificate authority
• * Certificate revocation list
• 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 key]s

• Brute force attack
• Dictionary attack
• Related key attack
• Key derivation function
• Key strengthening
• Password
• Password-authenticated key agreement
• Passphrase
• Salt
• Factorization

  [Cryptographic hash function]s

• Message authentication code
• Keyed-hash message authentication code
• * Encrypted CBC-MAC - NESSIE selection MAC
• * HMAC - NESSIE selection MAC; ISO/IEC 9797-1, FIPS PUB 113 and IETF RFC
• * TTMAC - NESSIE selection MAC; K.U.Leuven & debis AG
• * UMAC - NESSIE selection MAC; Intel, UNevada Reno, IBM, Technion, & UC Davis
• MD5 - one of a series of message digest algorithms by Prof Ron Rivest of MIT; 128-bit digest
• SHA-1 - developed at NSA 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; CRYPTREC recommendation
• * SHA-256 - NESSIE selection hash function, FIPS 180-2, 256-bit digest; CRYPTREC recommendation
• * SHA-384 - NESSIE selection hash function, FIPS 180-2, 384-bit digest; CRYPTREC recommendation
• * SHA-512 - NESSIE selection hash function, FIPS 180-2, 512-bit digest; CRYPTREC 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; CRYPTREC recommendation
• RTR0 - one of Retter series; developed by Maciej A. Czyzewski; 160-bit digest
• Tiger - by Ross Anderson et al.
• Snefru - NIST hash function competition
• Whirlpool - NESSIE selection hash function, Scopus Tecnologia S.A. & K.U.Leuven

  [Cryptanalysis]

Classical

• Frequency analysis
• 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
• *Chosen-plaintext
• *Ciphertext-only
• *Known-plaintext
• Side channel attacks
• * Power analysis
• * Timing attack
• * Cold boot attack
• Network attacks
• * Man-in-the-middle attack
• * Replay attack
• External attacks
• * Black-bag cryptanalysis
• * Rubber-hose cryptanalysis

  Robustness properties

• Provable security
• Random oracle model
• Ciphertext indistinguishability
• Semantic security
• Malleability
• Forward secrecy
• Forward anonymity
• 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 Publication Program - run by NIST 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
• International Organization for Standardization - standardization process produces many standards in many areas; some are cryptography related, ongoing
• Institute of Electrical and Electronics Engineers - standardization process produces many standards in many areas; some are cryptography related, ongoing
• Internet Engineering Task Force in many areas; some are cryptography related, ongoing)

  General cryptographic

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

  Open efforts

• Data Encryption Standard - NBS selection process, ended 1976
• RIPE - division of the RACE project sponsored by the European Union, ended mid-1980s
• Advanced Encryption Standard - a "break-off" competition sponsored by NIST, ended in 2001
• NESSIE Project - an evaluation/selection program sponsored by the European Union, ended in 2002
• eSTREAM- program funded by ECRYPT; motivated by the failure of all of the stream ciphers submitted to NESSIE, ended in 2008
• CRYPTREC - 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

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 regarding the PGP software.
• Export of cryptography
• Key escrow and Clipper Chip
• Digital Millennium Copyright Act
• Digital Rights Management
• Patents
• * RSA - now public domain
• * David Chaum - and digital cash
• Cryptography and law enforcement
• * 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

  Allied sciences

• Security engineering