Type once – see many ciphers at a glance. Toggle Encode/Decode to switch direction.
| Cipher | Type | Parameters | Properties | Notes |
|---|---|---|---|---|
| Caesar | Shift substitution (monoalphabetic) | Shift ∈ [0..25] | Linear over Z/26Z; reversible | ROT13 is Caesar with shift 13 |
| ROT5/13/18/47 | Involutive rotations | Digits (5), Letters (13), Alnum (18), ASCII 33–126 (47) | Self‑inverse (decode == encode) | Convenience encodings; not secure |
| Atbash | Mirror substitution | None | Self‑inverse | A↔Z, B↔Y, … preserves case |
| Affine | Linear substitution (monoalphabetic) | a (coprime 26), b ∈ [0..25] | Reversible iff gcd(a,26)=1 | Decoding uses modular inverse of a |
| Vigenère | Polyalphabetic substitution | Key (letters) | Repeating‑key shifts | Classical; not secure vs. Kasiski/IC |
| Enigma (M3) | Rotor machine (polyalphabetic) | Rotors, positions, rings, reflector, plugboard | Encode==Decode with same settings | Simplified stepping model for demo |
| Scytale | Transposition | Columns | Columnar read/write | Ancient rod cipher; reversible |
| Rail Fence | Transposition (zig‑zag) | Rails | Zig‑zag patterning | Symmetric with known rails |
| Keyboard Map | Layout mapping (non‑crypto) | JIS/US right‑neighbor | One‑to‑one char remap | Illustrative only (no secrecy) |
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