Rail Fence Cipher, Kartoniert / Broschiert

Klappentext

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Rail Fence Cipher (also called a zigzag cipher) generally refers to a form of transposition cipher. It derives its name from the way in which it is encoded. In the rail fence cipher, the plaintext is written downwards and diagonally on successive "rails" of an imaginary fence, then moving up when we reach the bottom rail. When we reach the top rail, the message is written downwards again until the whole plaintext is written out. The message is then read off in rows. For example, if we have 3 "rails" and a message of 'WE ARE DISCOVERED. FLEE AT ONCE', the cipherer writes out: The rail fence cipher is not very strong; the number of practical keys is small enough that a cryptanalyst can try them all by hand. The term Zigzag cipher may refer to the Rail Fence Cipher as described above. However, it may also refer to a different type of cipher system that looks like a zigzag line going from the top of the page to the bottom. As described in Fletcher Pratt's Secret and Urgent, it is "written by ruling a sheet of paper in vertical columns, with a letter at the head of each column.