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## Cryptology 101: Rail Fence

A cache by yukionna Message this owner
Hidden : 7/19/2009
Difficulty:
Terrain:

Size:  (regular)

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### Geocache Description:

The cache is not located at the posted coordinates. You must decipher the ciphertext, in the Puzzle section below, to obtain the actual coordinates of where the cache is hidden. The posted coordinates are the suggested parking area with room for two cars. Please don't block the gate.

## Background

This is another cache in my series of cryptology puzzle caches with the goal of demystifying some of the techniques used for solving and creating puzzle caches.

This puzzle cache is a transposition cipher called Rail Fence. In the rail fence cipher, the plaintext is written downwards and diagonally on successive "rails" of an imaginary fence, then moving up when the bottom rail is reached. When the top rail is reached, 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 "THE CACHE IS UNDER THE BIG ROCK", then the message is set-up as follows:

T . . . A . . . I . . . D . . . H . . . G . . . K
. H . C . C . E . S . N . E . T . E . I . R . C .
. . E . . . H . . . U . . . R . . . B . . . O . .

The three rows are read off one by one and grouped in any order. In this example, I grouped them in three groups -- each grouping depicts a rail -- which makes this puzzle easier to solve.

 TAIDHGK  HCCESNETEIRC  EHURBO

I could have grouped the letters in groups of four which would make the cipher a little bit more difficult to solve because the number of rails wouldn't be as straightforward:

 TAID  HGKH  CCES  NETE  IRCE  HURB  O

Transposition ciphers like this one are easily decrypted as the number of keys (i.e., the number of rails) is usually between three and seven so that different solutions can be quickly tried and deciphered.

## Puzzle

Decipher the following rail fence cipher to obtain the coordinates to where the cache is hidden. Good luck and have fun!

 North Coordinates NRFFZNS.  FUTOIEOREOIEI.  OWVURNX West Coordinates WERVNUOR  SVNEOIEIEORWFU  EZFNFTO

You can check your answers for this puzzle on Geochecker.com.

## Cache

The cache is a 6" x 8" clear plastic lock 'n lock located in the John D. Eaton State Forest in East Kingston, NH. The hike into the cache is along a logging road in the Eaton State Forest which is located next to the Hog Hill Swamp area.

Additional Hints (Decrypt)

Qba'g trg fghzcrq

Decryption Key

A|B|C|D|E|F|G|H|I|J|K|L|M
-------------------------
N|O|P|Q|R|S|T|U|V|W|X|Y|Z

(letter above equals below, and vice versa)

Find...

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Rendered From:Unknown
Coordinates are in the WGS84 datum

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