The public ledger
Every time someone seals a work, it writes one permanent line here, called a leaf. The ledger is public so anyone can check a seal, and it holds only fingerprints, never your work itself.
41
Entries sealed
#41
Latest leaf
8/13/2026
Ledger started
Look up an entry
Enter a leaf number to open that entry, or paste a work's 64-character fingerprint to find it in the ledger.
Have a file instead, and want to check whether it is sealed? Verify a file →
How the ledger works
A fingerprint, not your file
When you seal a work, your browser computes a SHA3-256 fingerprint of it. Only that fingerprint is sent. Your file never leaves your device, so the ledger cannot expose your work, only prove it existed.
One permanent leaf, chained to the last
The fingerprint, a timestamp, and a link to the entry before it are written as a leaf. Each leaf carries the hash of the one before, so the whole history is a chain: change any past entry and every later link breaks.
Signed to survive quantum computers
Each entry is signed with post-quantum keys, the kind built to hold up even after quantum computers arrive. The receipt you keep is verifiable by anyone, forever, with no account and no trust in us.
Check it yourself
Open any leaf to see its fingerprint, timestamp, and chain position. Or bring a file to the verify page and confirm its fingerprint matches a sealed entry. Nothing here asks you to take our word for it.