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Caesar Cipher (ROT13)

A simple substitution cipher that shifts letters by a fixed number of positions in the alphabet.

CryptographyAlso called: "rot13", "shift cipher", "substitution cipher"

The Caesar cipher is one of the oldest and simplest encryption techniques.

How it works

  • Each letter is shifted by N positions (ROT13 shifts by 13).
  • A → N, B → O, C → P (for ROT13).
  • Numbers and special characters unchanged.
  • Applying ROT13 twice returns original text.

ROT13 specifics

  • Shift by 13 positions (half the alphabet).
  • Self-inverse: encrypt and decrypt are identical.
  • Used to obscure spoilers, hints, answers.

Security

  • Not secure for real encryption!
  • Trivial to break (only 26 possible shifts).
  • Use only for obfuscation, not security.
  • Educational tool for learning cryptography basics.