Open Enigma Project: Build your own encryption machine

Enigma machines have captivated everyone from legendary code breaker Alan Turing and the dedicated cryptographers from England's Bletchley Park to historians and collectors the world over.

But while many history buffs would surely love to get their hands on an authentic Enigma machine used during WWII, the devices aren't exactly affordable (last year, a 1944 German Enigma machine was available for auction at Bonhams with an estimated worth of up to $82,000). Enter the "="" rel="noopener nofollow" class="c-regularLink" target="_blank">Open Enigma Project, a kit for building one from scratch.

The idea came to Marc Tessier and James Sanderson from S&T Geotronics by accident.

"We were working on designing and building intelligent Arduino-based open-source geocaching devices to produce a unique interactive challenge at an upcoming Geocaching Mega Event," Tessier told Crave. "A friend of ours suggested we use an Enigma type encrypting/decrypting machine as the ultimate stage of the challenge and pointed us to an Instructables tutorial that used a kid's toy to provide some Enigma encoding. We looked all over to buy a real Enigma machine even if we had to assemble it ourselves and realized that there was nothing available at the moment. So we decided to build our own."

"Convinced that very few would care," they then decided to produce their own Instructables tutorial and mentioned that if there was enough interest, they would produce a printed circuit board. "Within 24 hours, we had been seen by 15,000 readers and received overwhelming feedback telling us how awesome this product was and asking for boards," Tessier said.

From all the Enigma machines used throughout history, the Open Enigma Project decided on the original Enigma M4 machine.

"The Enigma, particularly the M4, is the most notorious encryption device of all time, as it served in the infamous German U-boat fleet and secured the most classified communications in the Third Reich," Sanderson told Crave. "We figured we should be able -- via software -- to emulate older models if we built the top of the line."

The original Enigma M4 machine was supplied with eight different coding wheels, with three wheels used at the same time along with a fourth permanent wheel. However, for the Open Enigma Project, the machine substitutes fine clockworks with quite a few impressive, high-tech upgrades.

"Our version is an electronic microprocessor-based machine that is running software which is a mathematical expression of how the historical mechanical machine behaved," Sanderson told Crave. "Having never touched a real Enigma M4, we built our open version based on what we read online. From what we understand, the real electro-mechanical devices are much heavier and a little bigger."

They took some design liberties -- replacing the physical rotors with LED units and replacing the light bulbs with white LEDs. The replica can be modified by changing the Arduino code and can communicate to any computer via USB. Future versions may include Wi-Fi and/or Bluetooth.

In addition to modern updates, the project is both open source and open hardware. "This product and others we come up with would not exist if it wasn't for the openness of the Arduino platform," Tessier said. "We make it open so we allow a community to form and assist with the development and improve the feature set of the products we create."

Modern-day cryptographers can learn quite a bit from the cryptographers who deciphered messages through the historic Enigma machine.

"Just like Edison, Alan Turing and his team at Bletchley Park came up through process of elimination of every way a light bulb or message cannot be made, Alan Turing is viewed as the father of modern computers -- but we prefer to see him as the first hacker," Tessier said. "Most modern hacking, decrypting, and key-breaking software and practices still revolve heavily around the fundamental methods invented by the Polish and Bletchley Park crew."

Cryptography fans, as well as war buffs, have been collecting original Enigma machines at the rate of tens of thousands of dollars per machine. So it's not surprising that the demand for cheaper and customized Enigma machines is encouraging to the Open Enigma Project creators.

"The Enigma machine has a notoriety through world history, is unavailable (unless you can afford $200,000), and is a unique piece of hardware," Sanderson said. "For the real replicas (physical rotors with authentic internal wiring), this is an ultimate challenge for the few ultra skilled to replicate. As for the electronic versions, maybe people love them because they are simple to assemble yet deliver complex encryption capabilities."