Cryptography20825 marksNumerical: Playfair cipher encryptionSubstitution Techniques
Given the key "HELLOWORLD", encrypt the plaintext "TURINGTEST" using Play fair cipher.
Given the key "HELLOWORLD", encrypt the plaintext "TURINGTEST" using Play fair cipher. [5]
- Key: HELLOWORLD - Plaintext: TURINGTEST - Cipher: Playfair (5x5 matrix, I/J combined) Key letters, removing duplicates (keep first occurrence): H, E, L, O, W, R, D (HELLOWORLD → H, E, L, [L dup], O, W, [O dup], R, [L dup], D) Fill remaining alphabet (I/J together): A, B, C, F, G, I/J, K, M, N, ...