Public ledger
Nobody can edit this. Including me.
Every certificate gets a hash that includes the hash of the one before it. Change one number, one date, one owner, and every hash after it breaks. The tip of the chain is anchored to the Bitcoin blockchain on a schedule with OpenTimestamps. No token, no wallet, no gas. Just math you can rerun.
Loading the chain…
Verify it yourself
hash = sha256(prev + "|" + number + "|" + seed + "|" + issued_at + "|" + owner) prev of #1 = 64 zeros · issued_at exactly as the API returns it (UTC, six fractional digits, Z suffix) owner = HMAC(secret, email): proves ownership to the holder without publishing the email
Pull the entries from /api/ledger?from=1&limit=1000 and follow next. Fold the formula over them. The last hash must match the anchored root.