In the demo above, the moment you commit (Roll-Dice) a commit with the hash of a player secret is sent to the server and the server accepts that and sends back the hash of its secret back and the "future" drand round number at which the randomness will resolve. The future used in the demo is 10 secs
When the reveal happens (after drand's particular round) all the secrets are revealed and the random number is generated using "player-seed:server-seed:drand-signature".
All the verification is in Math, so truly trust-less, so:
1. Player-Seed should matches the player-hash committed
2. Server-Seed should matches the server-hash committed
3. Drand-Signature can is publicly not available at the time of commit and is available at the time of reveal. (Time-Locked)
4. Random number generated is deterministic after the event and unknown and unpredictably before the event.
5. No party can influence the final outcome, specially no "last-look" advantange for anyone.
I think this should be used in all games, online lottery/gambling and other systems which want to be fair by design not by trust.
Are you sure? The protocol described in Chuck Norris book Applied Cryptography seems to work fine without a randomness beacon. Once you get the commitments from all parties they reveal the nonces and everyone verifies they match the commitments and extracts the same random bits.
In a standard 2-party commit-reveal, one party always learns the result first. (Mostly servers in current setups).
By adding a Randomness Beacon (Drand) as a third entropy source, we solve two things: No Last-Look: Neither the player nor the server knows the outcome until a specific future timestamp (the Drand round). Forced Resolution: Since the Drand signature is public, once that round passes, the result is 'locked' by math. The server can't hold the result hostage because anyone can pull the Drand signature and verify the result themselves.
Error: JSON.parse: unexpected character at line 1 column 1 of the JSON data
Commitment already pending for Round 26020619. Please wait for settlement before starting a new round. Error: The string did not match the expected pattern.