The Leftover Coded Messages Of WWII: Why It Took Decades To Solve Secret German Messages

The Codes Finally Get Cracked

Monthly key list Number 649 for the German Air Force Enigma, including settings for the reconfigurable reflector.

Monthly key list Number 649 for the German Air Force Enigma, including settings for the reconfigurable reflector.

So, what was the world to do? With no code book or information from the German military or its intelligence, and no expert codebreakers able to uncover the hidden messages hiding in those three mysterious groups of text, was there no answer to ever be found? Although it took decades, all one of these unbroken codes needed was a bit of modern technology and an interested amateur cryptographer.

About 50 years after World War II, a cryptography journal titled Cryptologia decided to publish three of the unsolved coded messages. This introduced the mystery – and challenge – to hundreds of thousands of individuals around the world, and opened up the possibility of breaking their code.

Countless readers of Cryptologia and codebreaking fans decided to try their hands at uncovering what had been hidden to the most skilled Allied code crackers during the war. Private individuals and cryptography organizations around the world offered contests for those interested in tackling these trickiest of messages. And suddenly, in 2006, a breakthrough occurred.

Scherbius's Enigma patent—U.S. Patent 1,657,411, granted in 1928.

Scherbius’s Enigma patent—U.S. Patent 1,657,411, granted in 1928.

Stefan Krah, a professional violinist born in Germany, surprised the world when he announced he had broken one of the unsolved messages from World War II. Krah wasn’t someone with an in-depth background in military intelligence, nor was he a skilled codebreaker; instead, he was simply a fan of cryptography, one who decided that he might be able to combine his love of cracking codes with his interest in open-source software.

When Krah came across the unsolved messages, he wrote a code-breaking software program named M4 (a name meant to honor the M4 Enigma machine that originally coded the messages) and reached out to fellow cryptology fans online.

Together, Krah and about 45 assistants got the program up and running on a grid of home computers all connected via the internet. As Krah’s software ran algorithms and tried millions of code combinations, it took the human effort out of the code-cracking process as it worked to recreate possible Enigma plugboard creations.

Finally, within a month of running his M4 program, Krah had a hit: the software successfully decoded the seemingly random letters of one of the wartime messages, uncovering a message long lost to history. The original code read in its encrypted state as: “NCZW VUSX PNYM INHZ XMQX SFWX WLKJ AHSH NMCO CCAK UQPM KCSM HKSE INJU SBLK IOSX CKUB HMLL XCSJ USRR DVKO HULX WCCB GVLI YXEO AHXR HKKF VDRE WEZL XOBA FGYU JQUK GRTV UKAM EURB VEKS UHHV OYHA BCJW MAKL FKLM YFVN RIZR VVRT KOFD ANJM OLBG FFLE OPRG TFLV RHOW OPBE KVWM UQFM PWPA RMFH AGKX IIBG.”

Once cracked by Krah’s M4 program, the message was revealed as: “Forced to submerge during attack. Depth charges. Last enemy position 0830h AJ 9863, [course] 220 degrees, [speed] 8 knots. [I am] following [the enemy]. [barometer] falls 14 mb, [wind] nor-nor-east, [force] 4, visibility 10 [nautical miles].”

When this exciting breakthrough was made, historians checked Krah’s message against the records of World War II – and the information in the once-hidden message was found to be correct. According to German records, the decoded message was easily verifiable. On November 25th, 1942, German Naval Commander Kapitanleutnant Hartwog Looks did send a message to others in the Navy, carefully encoded and encrypted in Enigma.

Heinz Guderian in the Battle of France, with an Enigma machine. Photo Credit.

Heinz Guderian in the Battle of France, with an Enigma machine. Photo Credit.

Can Krah Crack the Code for Good?

Stefan Krah’s software program brought an incredible breakthrough, one more than half a century in the making. The M4 program succeeded where countless trained, experienced, and highly intelligent codebreakers could not – but, as Krah remarked to BBC News, it’s not because the program is more intelligent or skilled.

Instead, M4 relies on a combination of “brute force” and trackable algorithms, and its speed enables it to move through hundreds of thousands of possible Enigma codes far faster than any human cryptography expert. With an ever-growing network of computers running M4, Krah and all those who run his program around the world are still hard at work cracking those last two messages from World War II.

Though the urgency and importance of these messages have faded with the resolution of that last world war, the codes still mystify and intrigue cryptographers and military intelligence alike. Despite the many Allied successes – and overall victory – throughout World War II, those deeply encrypted messages still shrouded in the Enigma Code represent just how difficult it was to intercept German intelligence so many years ago.

Still known today as one of the most foolproof codes in history, the Enigma Code was an incredible feat for those who cracked its messages and remains something of a mystery as we work to uncover the very last remnants of its existence today.