Substitution Cipher
A monoalphabetic substitution cipher replaces every letter of the plaintext with a different letter of the alphabet. Solve it manually, or let the autosolver find the key automatically with a Rust/WebAssembly simulated-annealing engine.
Type the plaintext letter that each ciphertext letter maps to. The mapping is applied instantly. Grey letters are unassigned.
How the autosolver works
The solver runs entirely in your browser via a WebAssembly module compiled from Rust. It models English with a smoothed 27-symbol (A–Z + space) quadgram language model, then performs multi-restart simulated annealing over the key space (each swap is rescored incrementally), refines candidates against a 370,000-word dictionary by pattern, and ranks the results. Word boundaries and an optional crib are respected. Nothing is uploaded — your ciphertext never leaves the page.