Cryptology

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Revision as of 22:25, 4 August 2008 by imported>Howard C. Berkowitz (Heisenberg's cat's revenge)
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Underlying principles

  • Information theory
  • Random numbers
  • Statistical characteristics of language
  • Computationally intractable problems

Methods of proving information is correct or has been transferred

Authentication

Sender authentication

Digital signatures
Key management
  • PKI
  • PGP

Server authentication

Nonrepudiation

Zero-knowledge proofs

Digital signatures

Confidentiality and integrity

Existence confidentiality

Traffic confidentiality

Message content confidentiality

Atomic and sequential integrity

Methods of concealing information

Cryptography

  • Ciphers and codes, including basic methods
  • Symmetric, asymmetric, and both
  • Key management protocols

Specific cipher implementations

Manual
  • Monoalphabetic substitutions
  • Polyalphabetic substitutions
    • Straddling methods
  • Transposition
  • Superencipherment
Mechanical/Electromechanical
  • Jefferson/Bazeries cylinder, strip ciphers
  • Vernam
  • Rotor and rotor-like: Hagelin, Enigma, Purple, SIGABA/Typex
Computer (general purpose and chip) implementations
  • General characteristics of military (KG vs KW, etc.)
  • Non-text/data: secure voice, video, fax
  • DES
  • PGP
  • AES

Steganography

  • Invisible ink methods?
  • Classic covert channel
  • Masking with graphics
  • Spread spectrum, frequency agility, {{seealso|electronic warfare))

Hybrid methods

Methods of obtaining partial or full information

See also: communications intelligence for things including traffic analysis and direction finding
  • Man-in-the-middle attack
  • Various general scenarios: brute force, chosen plaintext
  • Basic mathematical cryptanalysis: frequency analysis, index of coincidence, Kappa test
  • Advanced mathematical cryptanalysis
  • Red/black engineering and other COMSEC supporting measures
See also: communications intelligence
  • "Practical cryptanalysis" (black bag job), radiofrequency MASINT#Unintentional Radiation MASINT (TEMPEST/Van Eck, etc.), acoustic cryptanalysis
  • "rubber hose cryptanalysis"
    • "This is the most powerful handgun in the world. I can't remember if I've fired five or six times. Feeling lucky, punk?" This is an example of quantum cryptanalysis, with the .44 Magnum chamber is loaded or not loaded, but Heisenberg requires one pull the trigger to find out.