Fair draws · LESSON 3
Unipicker's draw-ledger — proof by record
Unipicker records every draw. The moment a draw starts, the draw materials (entrant info · draw settings) get sealed with a hash code, and the DRAND Round info to be used for the draw seed is posted to the ledger in advance. Once the draw ends, you can check the DRAND number and the draw's random seed.
Draw start = seal — The moment a draw starts, the entrant info and draw settings get sealed with a hash code. And the DRAND Round to be used for the seed is also posted to the ledger in advance. After sealing, secretly changing the data makes the hash differ and get caught instantly, and since the DRAND round is already public, the organizer can't know or pick the result in advance. In short, the draw materials get locked into an "unchangeable state" the moment the draw starts.
Policy
What is the draw-ledger?
The draw-ledger is a policy of publishing a host's draw history to stop them from repeating a draw until they get the result they want.
Join and get a dedicated ledger pageJoin the ledger and a member's own draw-history page is created; on each completed draw, the record is registered automatically.
Prevent repeat draws on one accountThe ledger can stop secret repeat draws on a single account.
Must disclose the URL at announcementLedger members must share the draw-history page URL with entrants when announcing results.
Because the history is public, "redraw until you like the result" is impossible — every attempt stays on the record.
Monitoring
Anti-fraud draw monitoring system
Unipicker runs an anti-fraud draw monitoring system for a fair draw. It automatically detects patterns like repeating similar draws or running a draw with fraudulent intent.
If the system detects a "fraudulent draw", use of the draw-ledger service is suspended, and you can no longer run ledger-registered draws.
Draw ledger
Explore the draw ledger
Standard draw-ledger example
100th anniversary prize winner draw
Entries201,448Winner100
Manager-run draw-ledger example
CERT-UNI8a7hV86LRun by Unipicker on behalf of the host2025 Glocal Edu Camp Participant Selection
Entries169Winner169
Draw manager
Kim Hea Ree
The seed info records the DRAND round · entrant-info file hash · draw-settings file hash · DRAND number · draw seed. Tap the items above to check.
Note — Unipicker uses DRAND first, NIST if DRAND fails, and Unipicker random if NIST fails too. Depending on which source was used, the items above may differ (e.g. NIST Pulse Index instead of DRAND Round).
With just this record, anyone can hash the list to compare with the seal, and recompute using that DRAND round value to verify the winners.
Draw seed info
Drand Round (14:57 KST round +2 · quicknet)
#28788954
Entrant-info file hash
758146c96b1c68fea22d4735167b02ad2502472126436b9a8861ecd5ad79b15c
Draw-settings file hash
345e196cd14c34fbf9c2ad44b93808aa174abc6327033532124d384ef480cf57
DRAND number
api.drand.sh actual value needed
Draw seed (first 16 hex of DRAND → decimal)
Computed after DRAND is finalized
Draw seed info
Drand Round (11:00 KST 라운드 +2 · quicknet)
#19427310
Entrant-info file hash
c1f9a7e2b0d4368a95ee72104f3b6ad81c2470ab55d9e3f6081cbe2a4d7f9061
Draw-settings file hash
7b3e0c9146af2d58e1046bd3927ac085f4d2136e90ba47c5382f1de6ac09b742
DRAND number
api.drand.sh actual value needed
Draw seed (first 16 hex of DRAND → decimal)
Computed after DRAND is finalized