local_offer Algebra Computers text cipher matrix Сryptography #billcipher #caesar #cipher #cryptography #cypher #decoder #gravityfalls #numbers #playfair #vigenere #Сryptography A1Z26 A2Z52 Bill Cipher Caesar Hill Hill cipher Language Playfair SVG Vigenere Vigenère cipher Wheatstone Wheatstone-Playfair ciphertext cryptography substitution cipher cypher decode decoder decryption numbers standard galactic alphabet substitution translator virtual keyboard