Monday, 27 December 2010

Rail Fence Cipher

By no means uncrackable or foolproof, but a nice encryption method to mess around with in your spare time.

For this example I will use three "rails" but in reality you could use as many as you wanted to. To encrypt the plaintext using a Rail Fence Cipher it is written downwards and diagonally, so say for example the plaintext was "CRYPTOGRAPHY" we would construct something like this:

C....P....G....P
..R....T....R....H
....Y....O....A....Y

The ciphertext is then formed from the letters on each "rail" or row, resulting in:

CPGP RTRH YOAY

As you can see this results in a challenging, yet fun cipher to crack as the job of the cracker is to determine the number of rails and correctly construct the plaintext.

1 comment:

  1. Good post! I think this method would be best used in conjunction with other encryption methods - like a hash function or a matrix method. That way, even if one could crack the plain text, they still have the rail fence to figure out.

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