This is Mary Tillotson.
And this is Steve Ember with the VOA Special English program EXPLORATIONS. Today we visit a small museum in the state of Maryland. It is called the National Cryptologic Museum. It is filled with information that was once very secret.
The little National Cryptologic Museum is on the Fort George G. Meade military base near Washington, D.C. It tells the story of cryptology and the men and women who have worked in this unusual profession. The word cryptology comes from the Greek "kryptos logos." It means "hidden word." Cryptology is writing or communicating using secret methods to hide the meaning of your words.
The museum shows many pieces of equipment that were once used to make information secret. It also has equipment that was used in an effort to read secret information. One unusual example is a kind of bed covering called a quilt. Quilts are made by hand. They usually have a colorful design sewn on them. One special kind of quilt was used to pass on secret information.
In the early history of the United States, black people from Africa were used as slaves in the southern states. Slaves sewed quilts that had very unusual designs. These quilts really told stories. The quilts were made with designs that told slaves how to escape to freedom in the northern states.
The museum has an example that shows a design that represents the North Star. Slaves knew they had to travel from the South to the North to escape to freedom. The quilt tells a slave to follow the North Star. Other designs in the quilt represent roads and a small house.
History experts say about sixty thousand slaves escaped to freedom during the period of slavery. The experts do not know how much the quilts really helped, but they did provide needed information for those trying to escape.
The Cryptologic Museum has several examples that show the importance of creating secret information, or trying to read secret information written by foreign nations. Secret information is also called code.
One of the most important displays at the museum shows American attempts to read Japanese military information codes during World War Two. The Japanese Navy used special machines to change their written information into secret codes. This coded information was then transmitted by radio to ships and bases. Much of this information contained secret military plans and orders.
The leaders of the Japanese Navy believed no one could read or understand the secret codes. They were wrong. An American Naval officer named Joseph Rochefort worked very hard to break the Japanese code. He did this in an effort to learn what the Japanese Navy was planning.
Mister Rochefort did his work in a small building on the American naval base at Pearl Harbor, Hawaii. It was early in nineteen forty-two. The American naval commander in the Pacific Ocean was Admiral Chester Nimitz. His forces were much smaller than the Japanese Naval forces. And the Japanese had been winning many victories.
Joseph Rochefort had worked for several months to read the secret Japanese Naval code called J-N-Twenty-Five. If he could read enough of the code, Mister Rochefort would be able to provide Admiral Nimitz with very valuable information. Admiral Nimitz could use this information to make the necessary decisions to plan for battle. By the early part of the year, Mister Rochefort and the men who worked with him could read a little less than twenty percent of the Japanese J-N-Twenty-Five code.
From the beginning of nineteen forty-two, the Japanese code carried information that discussed a place called "A-F." Mister Rochefort felt the Japanese were planning an important battle aimed at "A-F."
But where was "A-F"? After several weeks, Mister Rochefort and other naval experts told Admiral Nimitz that their best idea was that the "A-F" in the Japanese code was the American-held island of Midway.
Admiral Nimitz said he could not plan an attack or a defense based on only an idea. He needed more information.
The Navy experts decided to try a trick. They told the American military force on Midway to broadcast a false message. The message would say the island was having problems with its water-processing equipment. The message asked that fresh water be sent immediately to the island. This message was not sent in code.
Several days later, a Japanese radio broadcast in the J-N-Twenty-Five code said that "A-F" had little water.
Mister Rochefort had the evidence he needed. "A-F" was now known to be the island of Midway. He also told Admiral Nimitz the Japanese would attack Midway on June third.
Admiral Nimitz used this information to secretly move his small force to an area near Midway and wait for the Japanese Navy. The battle that followed was a huge American victory. History experts now say the Battle of Midway was the beginning of the American victory in the Pacific. That victory was possible because Joseph Rochefort learned to read enough of the Japanese code to discover the meaning of the two letters "A-F."
One American code has never been broken. Perhaps it never will. It was used in the Pacific during World War Two. For many years the government would not discuss this secret code. Listen for a moment to this very unusual code. Then you may understand why the Japanese military forces were never able to understand any of it.
You may have guessed that the code is in the voice of a Native American. The man you just heard is singing a simple song in the Navajo language. Very few people outside the Navajo nation are able to speak any of their very difficult language.
At the beginning of World War Two, the United States Marine Corps asked members of the Navajo tribe to train as Code Talkers.
The Cryptologic Museum says about four hundred Navajos served as Marine Corps Code Talkers during the war. They could take a sentence in English and change it into their language in about twenty seconds. A code machine at that time took about thirty minutes to do the same work.
The Navajo Code Talkers took part in every battle the Marines entered in the Pacific during World War Two. The Japanese were very skilled at breaking codes. But they were never able to understand any of what they called "The Marine Code."
For many years after the war, the American public did not know about the valuable work done by the Marine Navajo Code Talkers. The United States government kept their work a secret and their language continued to be a valuable method of passing secret information.
The Cryptologic Museum has many pieces of mechanical and electric equipment used to change words into code. It also has almost as many examples of machines used to try to change code back into useful words.
Perhaps the most famous is a World War Two German code machine called the Enigma. The word "enigma" means a puzzle or a problem that is difficult to solve.
The German Enigma machine was used by the German military to pass orders and plans. The United States, Britain, and the government of Poland were all successful in learning to read information transmitted by the Enigma. It took thousands of people and cost millions of dollars to read the Enigma information. However, the time, effort and money resulted in a quicker end to the war against Nazi Germany.
The National Cryptologic Museum belongs to the United States National Security Agency. The agency is usually called the N.S.A. One of the N.S.A.'s many jobs is cryptography for the United States government. The work of the N.S.A. is not open to the public. However, the National Cryptologic Museum tells the story of the men and women who work at the N.S.A. long after their work is no longer secret.
Each part of the museum shows the value of this secret, difficult and demanding work. Visitors say it is really fun to see equipment and read documents that were once very important and very, very secret.
This program was written by Paul Thompson. It was produced by Cynthia Kirk. I'm Steve Ember.
And I'm Mary Tillotson. Join us again next week for EXPLORATIONS, a program in Special English on the Voice of America.