On-Chain Games
Last updated
Last updated
The primary advantage of Fully Homomorphic Encryption (FHE) is its ability to improve application privacy, which can significantly enhance the appeal of certain gaming scenarios.
Integrating zkFHE with games offers new possibilities by enabling privacy features that allow on-chain simulations of traditional desktop games or creating variations like "fog-of-war" mechanics. These variations introduce elements of surprise and excitement, leading to increased player engagement and enjoyment. Below is an example of such an integration.
Most poker games can be developed on-chain with privacy measures, such as FHE, to replicate the confidentiality found in offline games.
Blackjack, also known as 21, is one such card game that could be adapted for the blockchain. The goal is to beat the dealer by either:
Having a hand value closer to 21 than the dealer's without exceeding 21, or
The dealer's hand exceeding 21 (busting), while your hand stays within the limit.
The basic rules are simple: Number cards (2-10) are worth their face value, face cards (Jack, Queen, King) are worth 10 points, and aces (A) can count as either 1 or 11, whichever benefits the hand.
The game has some flexible rules like doubling down, surrendering, or splitting cards, but for this example, we'll focus on integrating zkFHE.
Game Setup
The Blackjack dApp integrates with the zkFHE network, requesting a shared public key (PK) from a zkFHE working group. A threshold-FHE algorithm is used to ensure the privacy of card values.
Initial Round
As in a standard game, each player and the dealer are dealt two cards. The dealer's first card (the "hole card") is encrypted using the shared public key (PK) and dealt face down to maintain privacy.
Player's Turn
Players can draw additional cards until they feel their hand is close enough to 21. If a player’s hand exceeds 21, they bust and lose the round.
Dealer's Turn
If the dealer has a blackjack (a combination of an ace and a 10-point card), they immediately reveal it and win the round. This can be accomplished by homomorphically comparing the dealer’s first card with a "J/Q/K/10" or "Ace," depending on the second card, and then publicly revealing the result by decrypting the card using threshold decryption.
By integrating zkFHE into on-chain games like Blackjack, players can enjoy the same privacy as offline games, with additional flexibility for creating variations. This approach provides the necessary confidentiality and enhances the overall gaming experience while preserving the excitement of traditional gameplay.
