Affine Cipher

What Is a Affine Cipher?

The Affine Cipher tool encrypts and decrypts text with the formula E(x) = (a·x + b) mod 26, a combination of a multiplication and a shift. The multiplier 'a' must be coprime with 26 so that decryption is possible. This free online tool is useful for Affine cipher, Affine cipher calculator, Affine encrypt decrypt. Common use cases include modular arithmetic, classical cryptography, puzzles, and cryptography education. It is designed for quick browser-based hashing, encoding, decoding, encryption testing, checksum comparison, identifier generation, and cryptography education. For production security, follow the algorithm's current standards, key-management requirements, and application-specific security guidance.