In a columnar transposition cipher, we write a message in a rectangle, row by row, and read message off, column by column, but permute the order of the columns. The order of the columns is the key to the algorithm.
In a columnar transposition cipher, we write a message in a rectangle, row by row, and read message off, column by column, but permute the order of the columns. The order of the columns is the key to the algorithm.