zkchess-interactive

npm i zkchess-interactive

This contract is an interactive version of game-verification.

This contract assumes that atleast one of the players is honest to gurantee that the games are played correctly.

Check out the contractv2 branch for the non-interactive version of the contract which does not assume honesty of any player.

Why interactive?

To fully verify the game like in contractv2, we have to generate all possible moves and verify each move.

With Interactive Proofs the players prove facts by providing evidence to the contract.

Some tricky situations handled are:

1. invalid king castling

   king passes through an attacked square while castling.

2. stalemate

   when a player is not in check but has no legal moves.

Methods to handle disputes are namely

1. reportIllegalCastling
2. claimStalemate
3. acknowledgeStalemateClaim
4. overrideStalemateClaimByCapturingKing
5. reportStalemateClaimByValidOpponentMove
6. defendStalemateClaim

Checkout the Chess.ts & PvPChessProgram.ts files

Elo-Rating For Scoring

After every match the players rating gets updated based on the elo rating formulae.

Calculation of Elo-Rating is done using Taylor Series Approximation.

Checkout the EloRating.ts file

How to run tests

Test using node version 18.18.0

npm run test
npm run testw # watch mode

How to run coverage

npm run coverage

License

Apache-2.0