Cryptography Extra 3 Flashcards
feistel block cipher, symmetric, 16 rounds, 64-bit block, w/56-bit key (also 3DES). The term “S-boxes” means substitution boxes, and they are simply look-up tables. Each S-box basically has a table that determines, based on the bits passed into it, what to substitute for those bits. Each item passed into the box is substituted with the item that matches it in the lookup table.
DES (feistel block cipher, symmetric)
This is a variation of DES that simply XORs another 64-bit key to the plaintext before applying the DES algorithm. The concept of simply XORing in an additional key is called whitening. This won’t improve a cipher’s resistance to brute force attacks, but will increase the confusion of the resultant text.
DESx (symmetric algorithm)
Feistel Cipher, varying key sizes from 32-448-bits w/64-bit blocks; 16 rounds, symmetric Block Cipher.
Blowfish (symmetric feistel cipher)
symmetric block cipher, key size : 128, 192, 256, 128-bit blocks, substitution permutation and uses 32 rounds.
Serpent (symmetric Block cipher)
symmetric cipher, key size up to 256-bits w/128-bit blocks, Feistel Cipher.
Twofish (symmetric feistel cipher)
unbalanced feistel, 32 rounds, 80-bit key to encrypt or 64-bit blocks to decrypt. symmetric algorithm.
Skipjack (unbalanced Feistel network w/32 rounds, symmetric algorithm)
symmetric cipher, 128-bit key and 64-bit block size, 8 rounds, Block Cipher
IDEA (symmetric block cipher)
symmetric algorithm. feistel cipher, 128-bit key and 64-bit block. 64 rounds. 2^32.
TEA (Feistel Cipher w/64 rounds, symmetric algorithm)
block cipher, 128-bit key w/64-bit block size, 6 rounds.
SHARK (symmetric algorithm)
message is divided into blocks and each block is encrypted separately, if you submit the same plaintext more than once you always get the same ciphertext.
ECB
