Back to CTF Tools

Caesar Cipher

Classic shift cipher with brute force

Caesar Cipher Tool

Encrypt and decrypt using the classic Caesar cipher with brute force attack capabilities

Caesar Cipher

Shift each letter by a fixed number of positions

Result

Common CTF Examples

Click to try these typical Caesar cipher challenges

ROT13 Example

Shift 13

SYNT{pnrfne_vf_rnfl}

Classic ROT13 flag

Shift 7

Shift 7

MSHZ{jhlzhy_jpwoly}

Caesar with shift 7

Shift 5

Shift 5

KQFL{hfjxfw_hnumjw}

Another common shift

Backwards Shift

Shift 22

DKCF{ywqoyk_oapdqn}

Negative shift (ROT4 backwards)

CTF Tips for Caesar Cipher

  • • ROT13 (shift 13) is the most common variant
  • • Try brute force if you don't know the shift
  • • Look for readable English words in results
  • • Caesar cipher preserves letter case and non-alphabetic characters
  • • Some CTFs use negative shifts (backwards rotation)
  • • Check for nested Caesar ciphers (multiple applications)