Show HN: Double blind entropy using Drand for verifiably fair randomness(blockrand.net)

8 pointsby rishi_blockrand2 hours ago4 comments

hackingonempty31 minutes ago
> The only way to get a trust-less random value is to have it distributed and time-locked three ways, player, server and a future-entropy.
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.
- rishi_blockrand20 minutes ago
  Great point—Schneier’s two-party protocol is the foundation... However, it suffers from the 'Last-Actor/Last-Look' problem in a client-server environment.
  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.
WatchDogan hour ago
Clicking the button sometimes displays an error:
```
    Error: JSON.parse: unexpected character at line 1 column 1 of the JSON data
```
Looking at the network tab, the POST request to the commit API returns a 409 error with the message:
```
    Commitment already pending for Round 26020619. Please wait for settlement before starting a new round.
```
- rishi_blockrandan hour ago
  Oh yes, its only one commitment per call... this is a UI handling issue, will resolve it... the backend by design only takes one commitment per player, till it is resolved/revealed... Thanks
  - WatchDogan hour ago
    This happened on the first click opening the page, no other commit request in progress from myself, although maybe it's conflicting with other users.
    rishi_blockrandan hour ago
    Oh ok... so then thats definitely a bug then... actually drand issues randomness every 3 seconds... so may be multiple on the same drand round has a bug... will correct that... Thanks
rishi_blockrand44 minutes ago
The current time (in the demo) is fixed around 10 secs, but it can be anything, minimum being 6 secs (as the fastest) Drand pulse is 3 second, and some latency buffer...
charv2 hours ago
Cool stuff! I seem to have found a bug — often when I roll, I get this error and no roll happens:
```
  Error: The string did not match the expected pattern.
```
- rishi_blockrandan hour ago
  Hmm... I have not been able to replicate that... Can u screenshot it ? Thanks for trying it out : )