# Browse Items (30 total)

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## M-94

The M-94 was a cipher device based off the polyalphabetic manual substitution cipher. It was created by US Army major Joseph Mauborgne in 1917 with inspiration from a similar device invented by Thomas Jefferson in 1795. In 1921, it was introduced to…

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M-94

## Frequency Analysis

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…

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Frequency Analysis

## Atbash Cipher

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.…

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Atbash Cipher

## Hill Cipher

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…

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Hill Cipher

## Route Cipher

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…

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Civil War, Route Cipher

## Rail Fence Cipher

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…

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Rail Fence Cipher

## Affine Cipher

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…

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

E(x) = The…

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Affine Cipher

## Pigpen Cipher

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…

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Civil War, Freemasons, Pigpen Cipher