Lock entries
The database locks the round before reading eligible entries, so late submissions cannot enter the snapshot.
Draw integrity
Lock. Hash.
Draw. Save.
XPOT locks a stable eligible set, hashes it, generates secure server entropy and saves every input needed to reproduce the selected index. We describe the mechanism precisely without calling it “provably fair” beyond what is publicly verifiable.
Commit the set
Eligible entries are ordered by creation time and ID. The canonical list is committed with SHA-256.
Generate entropy
The server generates 256 bits with a cryptographically secure random source. The value is revealed after selection.
Select and save
A second SHA-256 value maps deterministically to a zero-based index. The draw and snapshot are immutable records.
Algorithm · sha256-index-v1
entries_hash = SHA256(id:handle | id:handle | …)
selection_hash = SHA256(entropy:entries_hash:sha256-index-v1)
selected_index = first_60_bits(selection_hash) mod eligible_count
Privacy and legal review are required before deciding whether the complete participant snapshot should be publicly downloadable. The immutable snapshot is retained server-side in Phase 2.