Zordle is a word-guessing game with a concentration on privacy that uses zero-knowledge proofs to ensure that the words being guessed by a player remain hidden from the verifier. Similar to the popular word-guessing game Wordle, but with an additional security layer.
A player and a verifier must first concur on a shared grid of letters in order to play Zordle. The player then attempts to predict a word that can be formed using some of the letters from the grid and uses a zero-knowledge proof to demonstrate to the verifier that they know a word that can be formed from those letters without revealing the actual word.
The Zordle zero-knowledge proof is based on the Halo 2 ZK proof system, a recent innovation in the field of zero-knowledge proofs that are designed to be efficient and scalable. By utilizing Halo 2, Zordle can provide robust privacy assurances without sacrificing performance.
Zordle is a free web application that can be accessed through any modern web browser. It was designed by a team of researchers at the University of California, Berkeley as a tool for teaching and investigating zero-knowledge proofs as well as a fun and engaging game.