There are two players: the codebreaker and the codemaster.

The codemaster creates a secret four-digit sequence of coloured pegs, limited to red, blue, green, and yellow.

To win, the codebreaker must guess the secret sequence of pegs within a set number of attempts. After each guess, if the codebreaker does not yet have the correct solution, the codemaster must tell the codebreaker the following clue:

• How many exact matches of colour and position there are — these are are black pegs

• How many pegs have matching colours, but are in the wrong position — these are white pegs.

For example, if the solution is R R B Y, and the guess is Y R B G, the codemaster must provide this clue: 2 black pegs and 1 white peg.

Solution : Y R B G Guess : R R B Y

Exact matches : 0 1 1 0 -> 2 black pegs Inexact matches: 0 0 0 1 -> 1 white peg Inexact matches do not overlap; for instance:

Solution : R R Y B Guess : G G R B

Exact matches : 0 0 0 1 -> 1 black peg Inexact matches: 0 0 1 0 -> 1 white peg (not two, even though there are two red pegs in the solution) Applied to the Mastermind board game, snarks could thereby prove that a clue about a secret combination of colours is correct, without revealing the secret itself.

In the implementation the hidden solution is an a array of 4 non-zero digits i.e ["1","2","3","4"] (say).

To reset the private solution run :

sh scripts/set_soln.sh

To play the game :

sh scripts/play.sh

It takes about 3-4 minutes to generate the proof which includes compilation of zok file,witness computation, proof generation and verifier contract generation.

• Reduction in proof generation time.
• Frontend to facilitate the game play.

• Hardhat
• Zokrates

• https://weijiek.medium.com/how-i-learned-zk-snarks-from-scratch-177a01c5514e
• https://zokrates.github.io/introduction.html