Caesar Cipher

Encrypt and decrypt text with a Caesar cipher that shifts letters by a set amount.

Category: Converters

When to use?

Use it to experience how a substitution cipher works for learning cryptography, or to simply hide text with ROT13.

How to use

  • Enter text.
  • Set the shift value (number of positions).
  • See the encrypted or decrypted result.

Input Explanation

Enter plaintext to encrypt or a Caesar ciphertext to decrypt, and set how many positions to shift.

Calculation Basis

It shifts each letter by the shift value. E.g. shift 3 gives A→D, B→E. Non-letters (numbers, symbols, non-Latin) are kept as-is.

Usage Examples

  • Simple encryption - Encrypt text with shift 13 (ROT13).
  • Learn ciphers - Experience how the substitution cipher, a crypto basic, works.
  • Hide spoilers - Hide answers or spoilers with ROT13 and decrypt when needed.

Examples

  • "Hello" + shift 3 → "Khoor"
  • "Hello" + ROT13 (shift 13) → "Uryyb"

Cautions

  • Malformed input can cause parsing errors or broken output.
  • A Caesar cipher is easily broken (only 26 cases), so use it for learning/fun, not real security.

Guides

Caesar cipher principle

It shifts each letter back by a set number to encrypt. For example, with a shift of 3, A→D, B→E, Z→C.

Strength and use

A Caesar cipher has only 26 cases and is easily broken by brute force. Use it for education, fun, or simple text hiding rather than security.

FAQ

Are non-Latin scripts encrypted?

A Caesar cipher supports only Latin letters; other scripts are kept as-is.

What is ROT13?

A Caesar cipher shifting 13 positions, where the same key both encrypts and decrypts.

Is a Caesar cipher secure?

No. With few cases it is easily broken, so use it for learning/fun, not real security.

Are uppercase and lowercase both handled?

Yes. It preserves case while shifting by the same amount.

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