Topics in cryptography

List of Topics in cryptography.

This article is intended to be an 'analytic glossary', or alternatively, a collection of pointers. See List of cryptology for an alphabetical listing of crypto articles and references in the Wikipedia.

Classical ciphers

• Autokey cipher
• Permutation cipher
• Playfair cipher (by Charles Wheatstone)

• Polyalphabetic substitution
  • Hill cipher
  • Vigenère cipher

• Substitution ciphers
  • Caesar cipher
  • Affine cipher
  • Atbash cypher

• Transposition ciphers
  • Scytale
  • grille cypher
  • VIC cipher (complex hand cypher used by at least one Soviet spy in the early 1950s -- it proved quite secure for the time)

Famous ciphertexts

• See Famous ciphertexts

Attacks on classical ciphers

• Frequency analysis
• Index of coincidence

Hash functions, aka message digest functions, cryptographic hash functions

• Cryptographic hash function
• Message authentication code
• Keyed-hash message authentication code
  • EMAC (NESSIE selection MAC)
  • HMAC (NESSIE selection MAC; ISO/IEC 9797-1, FIPS and IETF RFC)
  • TTMAC aka Two-Track-MAC (NESSIE selection MAC; K.U.Leuven (Belgium) & debis AG (Germany))
  • UMAC (NESSIE selection MAC; Intel, UNevada Reno, IBM, Technion, & UCal 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 has released several variants with longer 'digest' lengths)
• SHA-256 (NESSIE selection hash function, FIPS 180-2, 256 bit digest)
• SHA-384 (NESSIE selection hash function, FIPS 180-2, 384 bit digest)
• SHA-512 (NESSIE selection hash function, FIPS 180-2, 512 bit digest)
• RIPEMD-160 (developed in Europe for the RIPE project, 160-bit digest)
• TIGER (by Ross Anderson et al)
• SNERFU
• Whirlpool (NESSIE selection hash function, Scopus Tecnologia S.A. (Brazil) & K.U.Leuven (Belgium))

Public key / private key encryption algorithms (aka asymmetric key algorithms)

• ACE-KEM (NESSIE selection asymmetric encryption scheme; IBM Zurich Research)
  • ACE Encrypt
• Chor-Rivest
• Diffie-Hellman
• El Gamal (discrete logarithm)
• Elliptic curve cryptography (dicrete logarithm variant)
  • PSEC-KEM (NESSIE selection asymmetric encryption scheme; NTT (Japan))
  • ECIES (Elliptic Curve Integrated Encryption System; Certicom Corp)
  • ECIES-KEM
• EPOC
• Merkle-Hellman (knapsack scheme)
• McEliece
• NTRUEncrypt
• RSA (factoring)
  • RSA-KEM (NESSIE selection asymmetric encryption scheme; ISO/IEC 18033-2 draft)
  • RSA-OAEP
• Rabin cryptosystem (factoring)
  • Rabin-SAEP
  • HIME(R)
• XTR

Public key / private key signature algorithms

• Digital Signature Algorithm (from NSA, part of the Digital Signature Standard (DSS))
• Elliptic Curve DSA (NESSIE selection digital signature scheme; Certicom Corp)
• Schnorr signatures
• RSA signatures
  • RSA-PSS (NESSIE selection digital signature scheme; RSA Laboratories)
• Nyberg-Rueppel signatures
• MQV protocol
• Gennaro-Halevi-Rabin signature scheme
• Cramer-Shoup signature scheme
• One-time signatures
  • Lamport signature scheme
  • Bos-Chaum signature scheme
• Undeniable signatures
  • Chaum-van Antwerpen signature scheme
• Fail-stop signatures
• Ong-Schnorr-Shamir signature scheme
• Birational permutation scheme
• ESIGN
  • ESIGN-D
  • ESIGN-R
• Direct anonymous attestation
• NTRUSign
• SFLASH (NESSIE selection digital signature scheme (esp for smartcard applications and similar); Schlumberger (France))
• QUARTZ

Key authentication

• Key authentication
• Public key infrastructure
  • X.509
• Public key certificate
  • Certificate authority
  • Certificate Revocation List
• ID-based cryptography
• Certificate-based encryption
• Secure Key Issuing Cryptography
• Certificateless Cryptography

Anonymous identification scheme

• GPS (NESSIE selection anonymous identification scheme; Ecole Normale Supérieure, France Télécom, & La Poste)

Secret key algorithms (aka symmetric key algorithms)

• Stream ciphers
  • A5/1, A5/2 (cyphers specified for the GSM cellular telephone standard)
  • BMGL
  • Chameleon
  • FISH (by Siemens AG)
  • WWII 'Fish' cyphers
    • Geheimfernschreiber (WWII mechanical onetime pad by Siemens, called STURGEON by Bletchley Park)
    • Schlusselzusatz (WWII mechanical onetime pad by Lorenz, called tunny by Bletchley Park)
  • HELIX
  • ISAAC (intended as a PRNG)
  • Leviathan
  • LILI-128
  • One-time pad (Vernam and Mauborgne, patented mid-'20s; at the boundary of stream cyphers)
  • Panama
  • Pike (improvement on FISH by Ross Anderson)
  • RC4 cipher (one of a series by Prof Ron Rivest of MIT)
  • SEAL
  • SNOW
  • SOBER
    • SOBER-t16
    • SOBER-t32
  • Wake

• Block ciphers
  • Block cipher modes of operation
  • Product cipher
  • Feistel cipher (block cypher design pattern by Horst Feistel)
  • Advanced Encryption Standard (NIST selection for the AES, FIPS 197, 2001 -- by Joan Daemen and Vincent Rijmen; also NESSIE selection for 128-bit block cypher)
  • Anubis (128-bit block)
  • BEAR (block cypher built from stream cypher and hash function, by Ross Anderson)
  • Blowfish (by Bruce Schneier, et al)
  • Camellia (NESSIE selection, 128-bit block cypher; NTT & Mitsubishi Electric)
  • CAST5 (one of a series of algorithms by Carlisle Adams and Stafford Tavares; they are adamant however that the name is not due to their initials)
  • CS-Cipher (64 bit block)
  • Data Encryption Standard (DES, FIPS 46-3, 1976)
  • Grand Cru (128 bit block)
  • Hierocrypt-3 (128 bit block)
  • Hierocrypt-L1 (64 bit block)
  • International Data Encryption Algorithm (IDEA -- J Massey and X Lai of ETH Zurich)
  • Iraqi Block Cipher (IBC)
  • KASUMI (64-bit block)
  • Khazad (64-bit block)
  • LION 9block cypher built from stream cypher and hash function, by Ross Anderson)
  • Lucifer cipher (by Tuchman et al of IBM, early 1970s; modified by NSA/NBS and released as DES)
  • Mars (AES finalist, by Don Coppersmith et al)
  • MISTY1 (NESSIE selection 64-bit block; Mitsubishi Electric (Japan))
  • Nimbus (64 bit block)
  • Noekeon (128 bit block)
  • NUSH (variable block length (64 - 256 bits))
  • Q (128 bit block)
  • RC6 (AES finalist, by Ron Rivest et al; variable block length)
  • RC5,
  • SAFER++64 (variable block length)
  • SC2000 (128 bit block)
  • Serpent (AES finalist, by Ross Anderson et al)
  • SHACAL-1 (256-bit block)
  • SHACAL-2 (NESSIE selection 256-bit block cypher; Gemplus (France))
  • 3-Way
  • Triple DES (by Walter Tuchman, leader of the Lucifer design team -- not all triple uses of DES increase security, Tuchman's does)
  • Twofish (AES finalist; by Bruce Schneier, et al)

• Polyalphabetic substitution machine cyphers
  • Enigma (WWII German rotor cypher machine -- many variants, many user networks for most of the variants)
  • Purple (highest security WWII Japanese Foreign Office cypher machine)
  • SIGABA (WWII US cypher machine)
  • 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 30s and into WWII)

• Visual cryptography

Breaking ciphers

• Passive attack
• Chosen plaintext attack
• Chosen ciphertext attack
• Adaptive chosen ciphertext attack
• Brute force attack
  • Cryptographic key length
  • Unicity distance
• Cryptanalysis
  • Meet-in-the-middle attack
  • differential cryptanalysis
  • linear cryptanalysis
  • slide attack cryptanalysis
  • algebraic cryptanalysis

Weak key issues

• Brute force attack
• Dictionary attack
• Key derivation function

Key transport/exchange

• BAN Logic
• Needham-Schroeder
• Otway-Rees
• Wide Mouth Frog
• Diffie-Hellman
• man-in-the-middle attack

Pseudo-random number generators

• Blum Blum Shub
• Yarrow (by Schneier, et al)
• Fortuna (by Schneieir, et al)
• ISAAC
• PRNG

Anonymous communication

• Dining cryptographers protocol (by David Chaum)
• Anonymous remailer
• pseudonymity
• anonymous internet banking
• Onion Routing

Terminology

• Cryptographic key
• Cipher
• Ciphertext
• Plaintext
• Code
• Tabula recta

Cryptographers

• See List of cryptographers

Uses of cryptographic techniques

• Commitment schemes
• Electronic voting
• Authentication
• Digital signatures

Misc

• Echelon
• Espionage
• IACR
• Ultra
• Security engineering
• SIGINT
• Steganography
• Cryptographers
• SSL
• Quantum Cryptography
• Crypto-anarchism
• Cypherpunk
• Key escrow
• Zero-knowledge proofs
• Random oracles
• Random oracle model
• Blind signature
• Blinding (cryptography)
• Digital timestamping

Free/Open Source crypto systems (ie, algorithms + protocols + system design)

• PGP (a name for any of several related crypto systems, some of which, beginning at acquisiton of the name by Network Associates, have not been Free Software in the GNU sense)
• GPG (an open source implementation of the OpenPGP IETF standard crypto system)
• SSH (Secure SHell implementing cryptographically protected variants of several common Unix utilities, First developed as open source in Finland by Tatu Ylonen. There is now OpenSSH, an open source implementation supporting both SSH v1 and SSH v2 protocols. There are also commercial implementations.
• IPSec (Internet Protocol Security IETF standard, a mandatory component of the IPv6 IETF standard)
• Free S/WAN (an open source implementation of IPSec)