Cryptograhpy - secret message between two parties
Crytanalysis - breaking cryptography - think - analysis - which is to remove complexity
Cryptology - cryptography and crytptanalysis
Block Ciphers: http://www.youtube.com/watch?v=OJuWOPSOOK4&feature=related
ECB - Electronic Code Book - Does not involve chaining - so input will always yield the same output. This makes it only good for small, short sensitivity-life data.
CBC - Cipher Block Chaining - Solves the problem with ECB about always producing the same output by introducing an IV (initialization vector).
CFB - Cipher Feedback Mode - Similiar to CBC but for streaming instead of block. It uses the ciphertext from the last block to XOR with this block - hiding the plain text.
OFB - Output Feedback Mode - Improvement of CFB
CTR - Counter Mode - Improvement of OFB
XOR - 1(true) if bits are different
Running Key - when the key is not as long as the message (which is usual), the key is repeated until it is
One time pad -> Vernam Cipher - key must be protected, >= message, resulting pad cannot be reused, random key gen
Stream ciphers do not alter the length of the message - block ciphers do as they pad the message to conform to block sizes
Clipper Chip: used the skipjack cipher. Was meant to give the government the ability to wiretap phones but didn't take.
Morris worm of 1988: While going to Cornell, Morris deployed the worm from MIT. He only meant to 'measure' the internet, but the worm reinfected computers over and over again, causing a DOS attack. He is now a professor at MIT.
Symmetric - Skytale (Spartans)-> Ceasar's Cipher -> Enigma (Germans WWI) -> Purple Machine (Japanese WWII) -> DES (32 rounds) -> IDEA(64 bit blocks, 128 bit key, used in PGP) -> MARS (IBM entrance for AES)-> Blowfish(64 bit blocks, 448bit key entrance for AES) -> AES (Rinjdael 128, 10 rounds)
Diffie-Hellman is just for key exchange -> used by ElGamal
Collision - when two files produce the same hash.
Clustering - different keys yield the same result
Transposition -> Diffusion - moving things around
Substitution -> Confusion
4 Components - certificate and registration authorities, repository and archive
Revoked -> Revocation List, and online certification status protocol
SET - Secure Electronic Transaction - x.509 derivative that didn't gain traction
HAVAL (variable bit), RIPEMD (europe version of MD4), MD Series(MD5 = 128 bit), SHA (>160 bit), TIGER (designed for 64 bit systems)
MD4 is for high-speed computations, MD5 is standard
DSS - Digital Signature Standard - 160 bits
S/MIME, PGP, PEM (uses AES or RSA), MSP
UUencode - encoding for email - to add support for binaries (attachments)
X.400 - standard for email (exchange)
WEP - RC4 - stream cipher - used because it was fast and exportable
Side Channel - attack the encryption device itself