# Frequency Analysis

## Dublin Core

### Title

Frequency Analysis

### Subject

Frequency Analysis

### Description

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 found than 'X'. In fact, 'E' is the most common letter of the English alphabet- appearing roughly 12% of the time in a given sample message compared to other letters.

The way that this analysis works is that by comparing the frequency of the alphabet applied to the ciphertext with the frequency of the plaintext alphabet, the analyst can began making estimations of what letter lines up with which. Once the analyst finds the key- the correct plaintext letter a ciphertext letter aligns with in the alphabet, they can shift the entire alphabet and be able to read the rest of the message.

The way that this analysis works is that by comparing the frequency of the alphabet applied to the ciphertext with the frequency of the plaintext alphabet, the analyst can began making estimations of what letter lines up with which. Once the analyst finds the key- the correct plaintext letter a ciphertext letter aligns with in the alphabet, they can shift the entire alphabet and be able to read the rest of the message.

### Creator

Unknown

### Source

https://crypto.interactive-maths.com/frequency-analysis-breaking-the-code.html

### Publisher

Crypto Corner

### Contributor

Daniel Rodriguez-Clark

### Format

.JPEG

### Type

Cipher

## Still Image Item Type Metadata

### Original Format

Analysis

### Collection

### Citation

Unknown, “Frequency Analysis,”

*Ciphers and Encryption*, accessed April 14, 2021, https://crypto.omeka.net/items/show/28.