Caesar Shift or Alphabetic Rotation
This tool rotates the letters in a message forwards in the alphabet by any amount. ROT-13 is a popular cipher that advances each letter by half the alphabet. This is one of most simplistic substitution ciphers.
A Caesar Cipher is one of the most simple and easily cracked encryption methods. It is a substitution cipher that involves replacing each letter of the secret message with a different letter of the alphabet which is a fixed number of positions further in the alphabet.
Because each letter is shifted along in the alphabet by the same number of letters, this is sometimes called a Caesar Shift.
When a letter in the message has a direct translation to another letter, frequency analysis can be used to decipher the message. For example, the letter E is the most commonly used letter in the English language. Thus, if the most common letter in a secret message is K, it is likely that K represents E. Additionally, common word endings such as ING, LY, and ES also give clues. A brute-force approach of trying all 25 possible combinations would also work to decipher the message.
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