A Summary in Fifteen Minutes mas y menos Cryptography A Summary in Fifteen Minutes mas y menos

History of Cryptography Egyptian nonstandard hieroglyphs Spartans Scytale Caesar cipher Religion text changed in numbers (Hebrew) Poly-alphabetic cipher

History Continued Arabs and the complex principles Europeans 1379 the first manual of crypto was written 1470 cipher disk was invented Leon Battista 1586 Blaise de Vigenere

World Wars WWI Zimmerman telegram Code Talkers WWII Enigma Alan Turing Tommy Flowers

Modern Cryptography A mathematical algorithm that takes plain text and changes it into cipher text, for security purposes.

Symmetric-Key Symmetric-key One strong algorithm Two key must be kept secret.

Stream ciphers Keystream XOR operation Linear feedback Nonlinear feedback Stop-and-go generator Shrinking generator

Block ciphers Fixed length Feistel cipher Rounding functions DES AES Substitution-permutation network

Asymmetric Key aka Public key William Joven Diffie-hellman RSA MIT UK

Diffie Joven Hellman Logic Piano

Cryptanalysis, cypherpunks Attacking cipher text Two types Professional and amateur Weaknesses Brute-force Linear cryptanalysis Differential cryptanalysis

Symmetric-asymmetric cryptography Hybrid encryption PGP, Pretty Good Privacy OpenPGP

Encrypted Logons SSH Secure Shell RLogon Kerberos MIT Timestamps Session key Secret key One-way Hash

Snake Oil for Sale Snake Oil is a term used to describe commercial cryptographic methods and products which are considered bogus or fraudulent.

What to look for Secret systems Techno-Babble Larger bit claims Cracking contests Claims of setting new standards