Question

5. Using the modified rail fence algorithm (matrix size 5 x 5), encrypt the following message. Plaintext message: Defend the east and south wall Use the following key word to Also show your results after 1st and 2nd stage. What is the final encrypted message? encrypt: 31254

Answer 1

Encryption in a transposition cipher, the order of the alphabets is re - arranged to obtain the cipher - text - In the rail fence algorithm the plain - text is written downwards and diagonally on successive rails of an imaginary fence - When we reach the bottom rail, we traverse upwards moving diagonally, after reaching the top rail, the direction is changed again. Thus the alphabets of the message are written in a Zig - Zag manner - After each alphabet has been written, the individual rows are combined to obtain the cipher - text plain text - Defend the east and south wall key - 5 times 5 cypher - text - Dhahete nt f tduwedes