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)
: To reverse the process, the recipient must multiply the ciphertext vector by the inverse of the key matrix. Key Constraints & Security The system treats plaintext as a series of
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 Key Constraints & Security The Hill Cipher, introduced
letters is converted into a number (e.g., A=0, B=1... Z=25). : This -component vector is multiplied by an key matrix.
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