Browse Items (13 total)

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 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 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 ADFGVX cipher was developed by Colonel Fritz Nebel and introduced in March 1918. Germany used it as a field cipher during WWI. It was named the ADFGVX cipher for the letters used to create ciphertext, chosen for their distinctiveness in morse…

The Atbash Cipher is a monoalphabetic substitution cipher that is relatively simple and does not require a key. Instead of a key, the substitution simply relies on reversing the alphabet. Therefore, 'A' becomes 'Z', 'B' becomes 'Y', and so forth.…

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…

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…

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 Affine Cipher is a form of substitution cipher that involves math. The shift of the alphabet- while transpositioning plaintext into ciphertext is determined by a mathematical equation. This equation is:

E(x) = (ax+b) mod m

E(x) = The…

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…