Question

use a method that is useful for breaking transportation/permutation ciphers explain why its useful

Answer 1

transposition ciphers are a type of permutation cipher, where the length of the key is the same as the length of the plaintext.and the Method that will be used is the DECRYPTION as we will use the decryption method in order to break the cypher text.

Example:

hellomynameisabubakarwelcome toHomeworkLib

This text will be  encipher by using the permutation that divides the message into the 5letter blocks,

hello mynam eisab ubaka rwelc ometo HomeworkLib

Because the numbers of the letters in the plaintext message is not a multiple of 5, the last block must be padded.In this example, the last block is padded

hello mynam eisab ubaka rwelc ometo HomeworkLib

Then we rearrange the letters of the blocks according to the following permutation: 12345 45132

The letter in the first position of the block (on the left) moves to position 3, the letter in position 2 moves to position 5, the letter in position 3 moves to position 4, the letter in position 4 moves to position 1, and the letter in position 5 moves to position 2. After the permutation is applied to the first block, we have: hello 12345 45132 ehllo When the permutation is applied to all the blocks, we obtain:

hello mynam eisab ubaka rwelc ometo HomeworkLib

So, the ciphertext message is :

olssv tfuht lpzhi bihrh ydlsj vtlav jolnn

PLEASE GIVE A THUMBS UP!!!!!!!!