ETAOIN SHRDLU - Using Letter Frequency to Decipher the Ciphered

Source: https://arpitbhayani.me/blogs/decipher-single-xor Date: 2020-06-21

Crack single-byte XOR ciphers! Learn how to decipher encrypted messages without the key using frequency analysis and Python.

Encryption is a process of encoding messages such that it can only be read and understood by the intended parties. The process of extracting the original message from an encrypted one is called Decryption. Encryption usually scrambles the original message using a key, called encryption key, that the involved parties agree on.

The strength of an encryption algorithm is determined by how hard it would be to extract the original message without knowing the encryption key. Usually, this depends on the number of bits in the key - bigger the key, the longer it takes to decrypt the enciphered data.

In this essay, we will work with a very simple cipher (encryption algorithm) that uses an encryption key with a size of one byte, and try to decipher the ciphered text and retrieve the original message without knowing the encryption key. The problem statement, defined above, is based on .