Inspired by the film, of the Robert Harris novel “Enigma”, starring Dougray Scott and Kate Winslet I decided to create an open-ended series of puzzle caches based around the use of an Enigma machine.

Browsing the web I stumbled across a superb piece of freeware, created by Dirk Rijmenants, a cryptography expert and software designer based in Belgium. It suited my purpose perfectly. Whilst playing with the html code for my original enigmacaching.org.uk website, Dirk contacted me, he was genuinely intrigued by the whole Geocaching scene and has since sent me details of another code breaking, machine emulator, the BC-52 that he felt could be used for a similar purpose. He was also kind enough to proof read the code on the coin before production and I will be sending a coin for him to keep as a token of my appreciation.

I didn’t want the puzzles to be to be too difficult and so the first two or three caches were designed to educate participants rather than test them. The first cache was in fact called “Enigma One [Training Program]”

The early caches depended on cachers deciphering a password set in Morse code, embedded as a sound file on the GC.com cache page. This password was then entered on the original enigmacaching website and the machine settings retrieved from here.

Later on, authentic looking codebooks were introduced; each wrapped in brown paper with Hessian string and stenciled “Top Secret”. These were obtained from a cache contained within a dummy electrical enclosure, bolted to my factory gatepost. The participants set their machines from this depending on the caches date of publication.

The caches were released sporadically, generally about a week or so apart and majored on cunning urban hides. The series soon acquired a dedicated following of so called “agents” competing for the prized FTF. Cache logs embellished with Enigma code and talk of “missions being accomplished” were adding to the general fervor.

The next development was a breeder cache. By now the regulars were quite adept in the use of the machine, so eight ready made micros were placed inside with instructions that they should be taken by anyone willing to hide and publish them using Enigma code. These were named “Sleeper Cells” and numbered 001-008 …Little did anyone realize at the time, that each one contained a piece of information that would be required to find the final part.

The final cache to date was a full sized briefcase hidden under a boardwalk. It went live during an event that I’d organized for the occasion called Enigma [RVP], RVP being military code for “Rendezvous Point”.

The series eventually extended to nine Enigma caches and eight “Sleeper Cells” plus an event. Unfortunately after the initial excitement the caches were rarely found and due to their complexity they are not really suited to visitors passing through the area. Many people from all over the world however solved the first three puzzles and even though they would never be able to visit the area, or claim a find, requested that I send them codebooks so that they could “virtually” continue the series…. This I found most gratifying.

I designed the coin to complement the series but it has been on the back burner for over a year now, so alas the caches have all been archived. However I feel that the coin has a greater purpose as a lasting reminder of the great work undertaken by the British and Allied Forces code-breakers based at Station-X, Bletchley Park, England during WW2. It has been estimated that their skill in deciphering the German codes shortened the war by two years thus saving many thousands of lives.

A new cache is soon to go live in the North West of England. To find it you will have to crack the code on the coin. So dust off your code breaking kit….”M” is back.