Browse Items (13 total)

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,…

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 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…

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 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…

The Playfair Cipher was created in 1854 by Charles Wheatstone, and named after Lord Playfair for promoting its use. Initially, it was rejected by the British Foreign Office for appearing complicated. Later, the military began to use it for being…

The Pigpen Cipher is a form of substitution cipher that uses symbols, rather than other letters. Although its origin is unknown, this cipher was most famously used by the Freemasons in the 18th century- to the point that some know it as the…

The Hill Cipher was developed in 1929 by Lester Hill. A digraph substitution cipher, it works using groups of letters to encrypt. However, it is different from other digraph substitution ciphers because it can work on different group sizes of…

Frequency Analysis is a method of code breaking that works to decipher all substitution ciphers. This methods relies on the fact that some letters of the alphabet are used more than other letters of the alphabet. For example, 'E' is more commonly…

The Caesar Cipher is one of the oldest ciphers, used by Julius Caesar to communicate with his generals. It works by shifting the alphabet down by a fixed number, or key. Due to the simplicity, it can be broken if the crypanalyst knows that a simple…