Caesar Cipher
Encrypt and decrypt text using the classic Caesar cipher with customizable shift values.
Configuration
113 (ROT13)25
Alphabet Shift
Original:
ABCDEFGHIJKLMNOPQRSTUVWXYZ
Shifted (+3):
DEFGHIJKLMNOPQRSTUVWXYZABC
Actions
Plaintext
0 characters
Letters: 0
Ciphertext
All Possible Shifts
Enter text to see all shifts
About Caesar Cipher
History
Named after Julius Caesar, who used it with a shift of 3
How it Works
Each letter is shifted by a fixed number of positions in the alphabet
ROT13
Special case with shift of 13, applying it twice returns original text
Encryption Formula
E(x) = (x + k) mod 26
Security
Very weak - easily broken by frequency analysis or brute force
Brute Force
Only 25 possible keys, can be broken in seconds
Modern Use
Educational purposes and simple obfuscation, not real security
Variations
Atbash cipher, Affine cipher, and other substitution ciphers
Examples:
Caesar's original (shift 3):
HELLO → KHOOR
ROT13 (shift 13):
HELLO → URYYB