Page 252 - CISSO_Prep_ Guide

algorithm secret; it should instead rely on
the secrecy of your keys.
• Feistel: developed Lucifer, which later
became DES.
• Wassenaar agreement: export rules based
on key length.
• Moore's law: processing speed doubles
every 18 months.
• IV: initialization vector.
• Some variations of block algorithms
need the output of the previous block
to process the current block. The IV
represents the “previous” block while
processing the first block.
• For stream algorithms, the key is
often constant. To make the
keystream different for each use, and
IV is employed to modify the key
before feeding it to the keystream
generator.

Encryption Systems
• Cryptographic algorithms
• Symmetric
• Block
• Stream
• Asymmetric
• Discrete logarithms
• Integer factorization
• Substitution cipher: Caesar (shift alphabet or
scramble).