How Much Do You Know About the Use of Codes in WWII?


By: John Miller

6 Min Quiz

Image: Pfreundtner

About This Quiz

World War II is often called a “total war,” because many of the countries involved were fighting for their very existence. In an effort to confuse the enemy — or to steal their messages — countries formed special units dedicated to creating or deciphering transmissions that were meant to be secret. Both sides had major successes and failures in cryptography. In this quiz, what do you really know about the use of secret codes during the Second World War?

In the decade before the war began, the Germans began honing multiple cipher systems and machines that would prove their worth. But other European nations, witnessing the rise of Nazism, immediately set about trying to crack those codes long before the first bombs fell. What do you know about the codes that the Third Reich used to protect its nefarious schemes? And how much do you know about the heroes who committed their minds to unraveling the complexities of German ciphers?

Because their necks were on the line, Europeans were the first to really begin breaking Axis communications. Americans, however, did plenty to assist the effort. Together, they built amazing machines meant to counter German brilliance. What do you know about the tools that cryptoanalysts used for their vital wartime efforts?

The codes of WWII are the stuff of spy movies and epic dramas. The men and women who crunched the numbers and assembled real information from scrambled data became legends in their own right. Take this WWII secret code quiz now!

What was the name of the most famous code making machine of WWII?

After WWI, a German engineer devised the Enigma machine, a rotary cipher machine that became invaluable to the Nazis in WWII. The Allies expended major time and effort trying to crack Enigma.


"Cryptanalysis" became very important during WWII. What’s that?

As codes became more complicated, so too did the efforts to break those codes. Cryptanalysis is codebreaking, and it became very sophisticated during the war.


Which country devised the famous Lorenz cipher machines?

C. Lorenz AG, an electronics company in Berlin, created Lorenz cipher machines that became commonplace in Nazi Germany. The Lorenz machines — and their downfall — are a major part of WWII lore.


At the beginning of the war, Germany sent most of its coded transmissions via what means?

Early in the war, Germany used physical landlines, which in some ways were more secure than radio. As the Nazi Reich spread, it switched to wireless transmissions that easily reached longer distances ... but were also vulnerable to the Allied codebreakers.


True or false: in the mid-1930s, Polish researchers managed to crack the Enigma machine.

The Poles were cracking the Engima even before the war began. But in the late ‘30s, the Germans made upgrades to Enigma, and the Poles couldn’t monetarily afford to address the complexities of the upgraded machines.


Which country organized the Government Code and Cypher School following World War I?

After WWI, Britain started the Government Code and Cypher School (GC&CS), which explored techniques of codebreaking. It was a small unit at first — but when WWII broke out, the group exploded in size and importance.


What was the Allied code name for high-level intelligence captured from German signals?

In WWII, "Ultra" was a keyword that denoted high-level information snagged from encrypted German transmissions. This information was "ultra" secret, and thus, the nickname came to life.


By 1940, Britain’s Government Code and Cypher School (GC&CS) was actively trying to break ____ different code systems.

By 1940, war was ravaging Europe and the GC&CS was working to break about 150 different diplomatic codes, all to help give the Allies a advantage in the war.


What was "Bletchley Park"?

During the war, the British organized codebreaker teams at Bletchley Park in Buckinghamshire. There, brilliant Allied codebreakers banged their heads against the walls, trying (often in vain) to break Nazi codes.


What was the purpose of the "bombe"?

In an effort to decipher Engima messages, British codebreakers made the "bombe" machine. Famous cryptoanalyst Alan Turing helped to devise the first bombe machine.


How were the Allies finally able to break the Enigma machine during the war?

Enigma was a fantastically complicated machine and virtually unbreakable. But German human error introduced flaws into the code procedure ... and the Allies pounced.


In addition to Germany, what nation used Enigma machines in WWII?

Germany’s ally, Japan, also used Enigma machines in the course of the war. For years, these machines made it much harder for the Allies to fully understand Axis messages.


How did the Allies gather most of their Ultra intelligence?

The Allies intercepted countless Axis radio transmissions — and their cipher machines decoded many of those messages. Some historians say these decoded messages turned the tide of the war in favor of the Allies.


Marian Rejewski was a famous cryptologist from which nation?

Marian Rejewski was a codebreaker and mathematician from Poland who understood the Enigma machine even before the war began. His insights later helped the Allies decode Engima’s finer points to gather incredibly important information.


What was the name of a collection of computers that the British used to decipher Lorenz codes?

As the war raged, the British created Colossus, a set of computers meant to tackle German Lorenz machine codes. The Colossus Mark 2 became functional just in time for D-Day.


In the war, what sort of information did British General Montgomery glean from intercepted Germany communications?

During the war, British intercepts determined that the Germans were low on men and supplies. That kind of information allowed General Montgomery to exploit Nazi weaknesses.


Lorenz cipher machines were used for what sort of messages?

Lorenz machines carried some of the most sensitive high-level messages between German commanders. Allied codebreakers snagged very important details in their work to crack the Lorenz.


During the war, the United States employed Navajo people and their language to transmit secret messages. They were called ____.

Hundreds of Navajo people used their native language to communicate top-secret messages for America. The "code talkers" are renowned for their wartime contributions.


The British bombe machine was used to figure out which important bit of information?

The bombe machine helped codebreakers understand the strength of German forces in Western Europe and Normandy. This information was invaluable in planning the D-Day invasion.


How were the Germany navy’s Enigma machines different from those used by the rest of the armed forces?

The German navy used a variant of the Enigma machine that had an extra rotor (read: additional complexity) that made its messages incredibly difficult to break. For a while, the Allies were totally stumped.


What codename did British codebreakers use for German cipher streams?

They all diligently worked to decipher "Fish." British codebreakers were obsessed with pinpointing the details of Fish so that they could figure out what the Germans were saying to each other.


The British created Colossus to break Lorenz ciphers. Colossus is often regarded as the world’s first _____.

Technology historians often call Colossus the first programmable computer in world history. By the time the war ended, the Allies had built 10 of these machines, all in an effort to crack Axis codes.


When did the Allies finally get their hands on a Lorenz cipher machine?

The Allies made a lot of logical guesses as to the way the Lorenz machine worked. But thanks to German precautions, the Allies never even saw one of these machines in person until the very end of the conflict.


How did the Germans attempt to thwart the effectiveness of Native American code talkers?

The Nazis knew America would use Native American code talkers even before war began — so they sent dozens of anthropologists to America to study Native Americans.


Why did German spies mostly fail in their efforts to understand Native American language in advance of WWII?

Native American languages are full of nuances and dialects too subtle for non-speakers to grasp on the fly. Thus, code talkers were highly successful in disguising messages during the war.


True or false: the Navajo were the only Native Americans who served as code talkers in WWII.

The Allies employed people from numerous Native American tribes as code talkers. The relative obscurity of the languages of tribes like the Lakota, Comanche and others to Europeans made it much harder for enemy code breakers to do their jobs.


British cryptanalyst Alan Turing not only played a major role in WWII codebreaking, he is also considered a pioneer of which technology?

Turing was a brilliant codebreaker, one who also had a dramatic impact on computer science. His innovations are often credited with sparking the artificial intelligence revolution.


During the war, Comanche code talkers used a term for Hitler that roughly translated to _____.

Everyone, even many Germans, knew Hitler was nuts. The code talkers incorporated it into regular use — Hitler was "crazy white man."


True or false: German cryptanalysts believed that the Allies broke Enigma during the war.

The Germans knew it was technically possible to break Enigma — but they didn’t believe that Allies would find such matters worth their time and money. They were wrong.


The codebreaking techniques of WWII contributed heavily to the development of which product?

The sciences and computational requirements of cryptography changed the course of electronics — and of computers in general. In the wake of the war, computer technology quickly evolved into the digital revolution of today.


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