Affine Cipher
Linear modular transform: E(x)=a·x+b (mod 26).
Atbash Cipher
Reverses the alphabet: A↔Z, B↔Y — encryption equals decryption.
Autokey Cipher
Key seeds itself from the plaintext for stronger polyalphabetic encryption.
Bacon Cipher
Encodes each letter as a 5-bit A/B binary pattern.
Beaufort Cipher
Reciprocal polyalphabetic cipher: C = (K − P) mod 26.
Caesar Cipher
Simple substitution with a fixed alphabet shift.
Columnar Transposition
Columnar reordering using a keyword sort.
Playfair Cipher
Digraph substitution using a 5×5 matrix derived from a keyword.
Rail Fence Cipher
Zigzag transposition across multiple rails.
Scytale Cipher
Ancient Spartan tool: writes in rows, reads by columns (key = column count).
Substitution Cipher
Monoalphabetic: each letter maps to a unique letter via a shuffled key alphabet.
Vigenère Cipher
Polyalphabetic substitution driven by a key.
How to start
- Pick a method (Caesar, Vigenère, etc.).
- Enter your text and set the key/shift.
- Try encrypt/decrypt and copy the result.
Fundamentals
Guide to learning ciphersFundamentals
What is a Cipher? Definition, History and Types
Discover what a cipher is, how it originated in antiquity, and the most important types in classical cryptography.
Read article →Fundamentals
What is Cryptography? Definition, Types and Modern Examples
A complete guide to cryptography: what it is, its branches (symmetric, asymmetric, hashing) and how it protects information today.
Read article →Fundamentals
Hashing Explained: What It Is, How It Works, and What It's Used For
Learn what a hash function is, how it turns data into unique digital fingerprints, and why it's critical for modern security.
Read article →