Caesar Cipher Decryption Tool: Decode Encrypted Messages Instantly

Decrypt Your Caesar Cipher Message

Enter the encrypted message you wish to decrypt.
Enter the number of positions the letters were shifted. For example, a key of 3 means 'D' was encrypted to 'A'.

Unlock secrets with our free **Caesar Cipher Decryption Tool**. Easily decode encrypted messages by entering the ciphertext and the shift key. Ideal for students, hobbyists, and anyone exploring basic cryptography. Get your plaintext instantly and understand how Caesar ciphers work.

Formula:

The Caesar cipher decryption formula involves shifting each letter of the ciphertext back by a specific 'key' number of positions in the alphabet.

  • C: Ciphertext character
  • K: Key (shift value)
  • P: Plaintext character

The decryption operation is: P = (C - K) mod 26 (for letters), where mod 26 ensures the result wraps around the alphabet. Non-alphabetic characters are typically left unchanged.

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