In transposition ciphers, the characters of the plain text are transposed. Let's look at the steps involved for this:
- Create the matrix and choose the size of the transposition matrix. It should be large enough to fit the plain text string.
- Fill in the matrix by writing in all of the characters of the string horizontally.
- Read all of the characters of the string vertically in the matrix.
Let's look at an example.
Let's take the Ottawa Rocks plain text (P).
First, let's encode P. For that, we will use a 3 x 4 matrix and write in the plaintext horizontally:
| O | t | t | a |
| w | a | R | o |
| c | k | s |
The read process will read the string vertically, which will generate the cipher text—OwctaktRsao.
The Germans used a cipher named ADFGVX in the First World War, which used both the transposition and substitution ciphers. Years later, it was cracked by George Painvin.
So, these are some of the types of ciphers. Now, let's look at some of the cryptographic techniques that are currently used.