Käytössä Mystery Cache

                                                                        A Railfence cipher

         I'll give you a quick history & tutorial on the RailFence Cipher so you will have little difficulty in reconstructing & deciphering.

The Railfence cipher is a method of transposing the letters of a message that has been around for a longtime. Usually the message is written into zigzag from a certain number of rows deep and taken out of the zigzags by rows (also called rails).

In the following example, we have 3 "rails" and a message of 'WE ARE DISCOVERED. FLEE AT ONCE', the cipherer writes out:

W . . . E . . . C . . . R . . . L . . . T . . . E
. E . R . D . S . O . E . E . F . E . A . O . C .
. . A . . . I . . . V . . . D . . . E . . . N . .

Then we read it out horizonatly & do the usual rearranging of the cipher letters into 5-letter groups as is common practice:

WECRL TEERD SOEEF EAOCA IVDEN

This is know commonally as the "W" form as the zigzags form a WWW Shape.

Another common varitaion is the "M" form (Also it can be thought of as an offset), which is basically the inverse and form a MMM Shape.

. . A . . . I . . . V . . . D . . . E . . . N . .
. E . R . D . S . O . E . E . F . E . A . O . C .
W . . . E . . . C . . . R . . . L . . . T . . . E

Another common variant is to change the amount of rails, which does little to change the difficulty but does add variation.

You can make it slighty more difficult by adding an offset. Instead of starting on the top rail and working down, you can start on any rail and move up or down depending on where you place the offset. The "M" Shape in the above example could also be thought of as an offset of 2.

You can validate your puzzle solution with certitude.