Get the key ideas from

Code Girls

The Untold Story of the American Women Code Breakers of World War II

By Liza Mundy
16-minute read
Audio available
Code Girls by Liza Mundy

Code Girls (2017) is about the thousands of American women who worked as code breakers during World War II. Informed by interviews with over 20 surviving women, archived documents, and recently declassified oral histories, author Liza Mundy details the unprecedented lives of female code breakers in Washington, DC and beyond as well as the American intelligence that led to the success of the Allied war efforts.

  • History buffs
  • Espionage enthusiasts interested in the history of cryptography
  • Students of science or gender studies

Liza Mundy is an award-willing journalist and author of the New York Times bestselling The Richer Sex: How the New Majority of Female Breadwinners Is Transforming Sex, Love and Family. She has contributed to publications such as TIME, the Guardian, the New Republic, and Slate and was previously a reporter at the Washington Post. As a senior fellow at the think tank New America, she is a leading expert on women and work issues.

Go Premium and get the best of Blinkist

Upgrade to Premium now and get unlimited access to the Blinkist library. Read or listen to key insights from the world’s best nonfiction.

Upgrade to Premium

What is Blinkist?

The Blinkist app gives you the key ideas from a bestselling nonfiction book in just 15 minutes. Available in bitesize text and audio, the app makes it easier than ever to find time to read.

Discover
3,500+ top
nonfiction titles

Get unlimited access to the most important ideas in business, investing, marketing, psychology, politics, and more. Stay ahead of the curve with recommended reading lists curated by experts.

Join Blinkist to get the key ideas from
Get the key ideas from
Get the key ideas from

Code Girls

The Untold Story of the American Women Code Breakers of World War II

By Liza Mundy
  • Read in 16 minutes
  • Audio & text available
  • Contains 10 key ideas
Upgrade to Premium Read or listen now
Code Girls by Liza Mundy
Synopsis

Code Girls (2017) is about the thousands of American women who worked as code breakers during World War II. Informed by interviews with over 20 surviving women, archived documents, and recently declassified oral histories, author Liza Mundy details the unprecedented lives of female code breakers in Washington, DC and beyond as well as the American intelligence that led to the success of the Allied war efforts.

Key idea 1 of 10

Cryptography bureaus often took on female workers because of the work’s grueling nature.

Cryptography, or code making, is as old as human communication itself. It dates back to some early point in time when a person first wanted to say something that not everyone was supposed to know.

Naturally, making codes is particularly useful in times of war. During the Civil War, for example, the Confederates devised a cryptographic system so complex that it confused even them.

In the early 1920s, however, American code breaking lagged behind that of countries such as France and England. In 1928, the US secretary of state even shut down military intelligence’s modest cipher bureau as it was bad manners to read other people’s mail.

But not everyone dismissed code breaking as immoral. And those who did see its purpose tended to favor women for the job. The assumption was that women were better able to focus intensely over long periods of time than men, who were seen as more intelligent but less patient. The assumption overlooked the fact that good code breaking requires both patience and intelligence.

In order to understand how code breaking works, let’s take a look at the two types of covert message systems: codes and ciphers. Codes are words, letters, or a string of numbers that represent words or phrases. Sometimes codes are used for brevity, in the same way that OMG is used today. But codes can also be used to disguise secret information from an enemy’s prying eyes; those meant to read the code could decipher it using a codebook.

Ciphers, on the other hand, are either a scrambling of letters known as transposition or a substitution of individual units with unique units – for example, substituting r for t. During the Renaissance, ciphers such as the Vigenère square were created by lining up various alphabets into a table that could be referenced. But with the development of radio and the telegraph, governments needed more security. So they created cipher machines as well as developing complicated ciphers using mathematical equations.

Tackling messages intercepted by cable, airmail, or teletype – that is, cryptanalysis, or code breaking – involved many tactics. In some cases, codes were cracked by stealing codebooks from the enemy. But more often, cryptanalysts cracked codes by studying the frequency and placement of specific words, using mathematical equations, and deducing meaning through educated guesses.

Upgrade to continue Read or listen now

Key ideas in this title

Upgrade to continue Read or listen now

No time to
read?

Pssst. Sign up to your secret to success: key ideas from top nonfiction in just 15 minutes.
Created with Sketch.