The system treats plaintext as a series of vectors and uses a square matrix as the encryption key. : Each letter in a block of
: The resulting values are taken modulo 26 (or the size of the character set) to stay within the alphabet range. Hill Cipher (Encryption)
The Hill Cipher, introduced by Lester S. Hill in 1929, is a polygraphic substitution cipher that applies linear algebra to cryptography. Unlike simple substitution ciphers that replace one letter at a time, the Hill Cipher encrypts groups of letters simultaneously using matrix multiplication. How It Works The system treats plaintext as a series of
: To reverse the process, the recipient must multiply the ciphertext vector by the inverse of the key matrix. Key Constraints & Security Hill in 1929, is a polygraphic substitution cipher
While historically significant for being the first cipher practical for blocks larger than three symbols, it has notable limitations: Hill Cipher Oracle Attack - LACTF2023 - crypto/hill-easy
letters is converted into a number (e.g., A=0, B=1... Z=25). : This -component vector is multiplied by an key matrix.