a year ago
Playfair Cipher is a symmetric key based encryption technique that uses digraph substitution cipher. This technique encrypts pairs of alphabets instead of single alphabets. Hence this cipher is harder to break. Rules: 1. Make a 5x5 matrix and fill it with the key and then all remaining alphabets. 2. Divide Plaintext(message) into lengths of two letters. Eg: attack becomes “at ta ck” 3. If the letter is repeated then add a filler letter. Eg: balloon becomes “ba lx lo on” 4. If the two letters are in the same row, then take the value in front of the letters. 5. If the two letters are in the column row, then take the value below the letters. 6. If the values form a rectangle, then take the last alphabet in respective rows.