Virtual Lorenz machine
The Virtual Lorenz machine has been designed to look, operate and even sound similar to the original device The National Museum of Computing

You can now try your hand at Germany's WWII cipher system. An online version of Hitler's "unbreakable" Lorenz crypto machine was unveiled by Britain's National Museum of Computing that allows you to try out the encryption system Hitler used to secretly communicate with his top generals.

The Virtual Lorenz machine was launched to commemorate the 100th birthday of Bill Tutte, the Bletchley Park mathematician who successfully reverse engineered the German High Command's Lorenz SZ42 cipher system, allowing the Allies to unravel top-secret coded messages.

"Tutte's work, often regarded as the greatest intellectual feat of the war, shortened the conflict by enabling the decryption of the enemy's strategic messages on a regular basis — and very rapidly with the help of Colossus computers," the National Museum of Computing said in a statement.

The Virtual Lorenz machine has been designed to look, operate and even sound similar to the original device and can be used by anyone with an internet connection.

Tutte and his colleague John Tillman managed to determine how the machine worked without even having seen the actual device, which was considered to be even more complex than the better known Enigma cipher machine.

The creator of the Virtual Lorenz Martin Gillow said that the inspiration for the online version of the German cipher machine came from Colossus computer.

"As a programmer, I was fascinated by the rebuild of Colossus computer when I first saw it at The National Museum of Computing," Gillow said. "Tony Sale, who led the rebuild team, had also created a Virtual Colossus for the web, but I discovered that it would only run on old browsers. Since Tony Sale had passed on, it was likely to become inaccessible and lost forever as web technologies progress.

"So, I decided to recreate the Virtual Colossus – and then a Virtual Lorenz to accompany it. It took months of work in my spare time, and revealing it to the audience at the Museum was a real thrill."

The Lorenz teleprinter
The teleprinter for the Lorenz cipher machine National Museum of Computing