Codes and Ciphers :: Route Cipher
A Route Cipher is very similar to a Rail Fence cipher with one exception. You still write the message vertically in columns, but instead of reading off the secret message horizontally, you read it off using a predetermined pattern. For example, lets use a spiral pattern for this one:
T S A C T S G H I S R M S E I S E E E A J
The last J is just a random letter to fill in the space. If we are using a clockwise spiral to read off the message, then it becomes:
A more complex pattern could be, "every other letter going backwards to the front and then every other letter going forwards to the end again", which would give you a secret message of:
The complex pattern makes this algorithm difficult to decipher unless you know the key.