Browse Items (30 total)

PURPLE was a Japanese cipher machine used during WWII and based off the Enigma's rotor technology. While it was developed in 1937 with four rotors (compared to the Enigma's three), it was broken only a few years later in 1940 without being seen by…

The Rail Fence Cipher is form of transposition cipher that scrambles the letters. It does this by using a grid of x many rows, and the sender writes the plaintext in the grid in a vertical zig-zag pattern. The key for this cipher is the number of…

A Route Cipher is a type of transposition cipher where you write the message into a grid box and read the letters in a certain route. This cipher was used by the Union forces during the Civil War. However, they took care to use it in a way that moved…

The scytale is known as the first cryptographic device, used in 400 B.C. by the Spartans. It consisted of a baton and a papyrus strips with letters. These papyrus strips would only reveal the message sent between Spartan generals if the baton they…

SIGABA was an electro-mechanical cipher machine created in the late 1930s by the US Army and Navy. It was considered an impressive cryptomachine in that time period to the degree that it was used throughout WWII and into the 1950s.

By the end of…

The Culper Code Book was used during The American Revolutionary War in 1778 by George Washington's Culper Spy Ring. Developed by Ben Tallmadge, it consisted of 763 numerical codes to represent various words, names, and locations. This code book was…

The Zimmerman Telegram, sent from Germany to Mexico during WWI, was intercepted and decoded by the British early 1917. It took them approximately a month to send the decoded message to the U.S. British intelligence decoded the message in Room 40 of…

The TypeX was an electromechanical cipher machine used by the British during WWII. It was devloped by Wing Commander O.G.W. Lywood, with the first production batch delivered to the RAF in 1937. As a British variant of the Enigma, versions of it came…

The Vigenère cipher was created in the 16th-century by French cryptographer Blaise de Vigenère. It was revered as "le chiffre indéchiffrable" or "the unbreakable cipher" for many years after its invention.

It works by concealing the original…

The WWII Pigeon Cipher describes a coded message found on the remains of a carrier pigeon discovered in 1982. This message was sent to the curator of the Pigeons at War exhibit at Bletchly Park, however he found it impossible to crack.

In 2012,…