Cryptanalysis - Paiet/Tech-Journal-for-Everything GitHub Wiki

Cryptanalysis is the art or process of deciphering coded messages without being told the key.

Frequency Analysis - examining ciphertext looking for patterns that can be examined against the frequency rate of letter usage by language.

Kasiski test - A variation on frequency analysis that is used to attack polyalphabetic substitution ciphers.

Chosen Plaintext Attack - attacker obtains the ciphertexts corresponding to a set of plaintexts. This can allow the attacker to attempt to derive the key used and thus decrypt other messages encrypted with that key.

Ciphertext Only Attack - attacker ONLY has access to the ciphertext of messages.

Related-Key Attack - Similar to the Chosen Plaintext Attack, except that the attacker is able to get messages encrypted with two different keys (the keys need to be related, meaning that one was derived from the other as is the case in wireless systems)

Linear Cryptanalysis - a known plaintext attack and uses a linear approximation to describe the behavior of the block cipher. Given sufficient pairs of plaintext and corresponding ciphertext, bits of information about the key can be obtained and increased amounts of data will usually give a higher probability of success. Invented by Mitsarue Matsui.

Differential Cryptanalysis - a form of cryptanalysis applicable to symmetric key algorithms. This was invented by Eli Biham and Adi Shamir. The examination of differences in an input and how that affects the resultant difference in the output.

Integral Cryptanalysis - Similar to Differential Cryptanalysis, but uses a different technique. Uses sets or even multisets of chosen plaintexts of which part is held constant and another part varies through all possibilities.

How do we measure success:

    Total break - attacker gets the key.
    Global deduction - attacker discovers a functionally equivalent algorithm for encryption and decryption, but without learning the key.    
    Instance (local) deduction - attacker discovers additional plaintexts (or ciphertexts) not previously known.
    Information deduction - attacker gains some information about plaintexts (or ciphertexts) not previously known.
    Distinguishing algorithm - attacker can distinguish the cipher from a random permutation.

Password cracking and Rainbow Tables -

http://project-rainbowcrack.com/table.htm