Your file stays with you.

Your file is never uploaded.

When you select a file, your browser calculates its SHA-256 fingerprint locally. The file itself is not sent to us or to anyone else. The same applies when you verify a file.

A fingerprint cannot be turned back into the file.

What a proof makes public.

When you create a proof, you send a transaction from your own wallet to the BlockchainProof smart contract on the Arc network. It records:

• the file's SHA-256 fingerprint;
• your wallet address;
• the block number and time; and
• the payment: 1 USDC, of which 0.10 USDC stays with the smart contract and 0.90 USDC goes to BlockchainProof, plus the network fee.

Arc is a public blockchain. Anyone can see these details and link a fingerprint to the wallet that recorded it. Blockchain records are permanent: nobody, including BlockchainProof, can change or delete them.

Your wallet address does not reveal your name by itself, but it may be linked to you through other activity, such as an exchange account or other transactions.

Nothing about you.

This website has no database, no user accounts and no sign-in. It does not set cookies and does not use analytics or advertising trackers. Proof pages, verification and "My proofs" read directly from the smart contract and the public blockchain each time you open them.

Like almost every website, our web server keeps standard access logs, such as IP address, browser type, time and the page requested. Proof page addresses include the fingerprint and wallet, so these appear in the logs. We use logs only to run and secure the site, and they are kept according to our hosting provider's standard log retention.

Temporary data, kept on your device.

• Pending proof. While a transaction is being confirmed, the page keeps its transaction ID, fingerprint and wallet address in your browser's session storage so it can resume if you reload. It is removed when the proof finishes and when you close the tab.
• Wallet connection. The wallet connector remembers your connection in your browser's storage (local storage and IndexedDB) so you stay connected. It does not use cookies. Disconnect in your wallet, or clear this site's data in your browser, to remove it.

Who else sees what.

To work without a server of our own, the site talks directly to these services from your browser. Each has its own privacy policy.

• Arc network nodes receive the blockchain requests your browser makes, such as looking up a fingerprint or wallet, and the transactions you send.
• ArcScan, the Arc block explorer, receives searches used to list proofs by fingerprint or wallet, and pages you open there.
• Reown (WalletConnect) provides the wallet connection window and relays connections to mobile wallets. Its analytics option is switched off on this site.
• Your wallet, such as MetaMask, handles your keys and shows you each transaction before you approve it.
• Our web host serves the pages and keeps the access logs described above.

These services only receive information that becomes public on the blockchain anyway, together with the usual technical details of an internet request, such as your IP address.

You decide what is recorded.

Nothing is recorded unless you approve the transaction in your wallet. You can verify files and view proofs without connecting a wallet.

Because we do not hold personal data about you, there is nothing for us to access, correct or delete on request, apart from server access logs. Records on the blockchain cannot be deleted by anyone once they are made.

Questions.

If this policy changes, we will update it on this page and change the effective date above.

For privacy questions, contact us at team@sarawallet.com.