# Phillips Cipher

Starting with a basic keysquare, the first row is shifted down one row at a time form squares #2,3,4 and 5. Row two is then shifted down a row at a time to form squares #6,7 and 8. Each square is used in turn to encipher 5 plaintext letters. Each pt letter is enciphered by taking as substitute the letter diagonally down to the right using the proper square, A pt letter in the 5th column is replaced by the letter from the first column and the row below it; a pt letter in the 5th row is replaced by the letter in the first row and to its right.