Instant, tamper-proof blockchain certificate for your files. 100% private - files never leave your browser.
Drop your file here or click to browse
PDF, PNG, JPG, ZIP, DOCX - up to 10MB
Your file never leaves your browser. Only a SHA-256 hash is sent.
No wallet? Start free.
A free unsigned receipt proves the file existed now. No signup, no payment - same receipt page, same verification.
0x97E9af6B4d8a49f509DA99afaB954429Ab8Cc800
Send exactly 0.10 USDC on Base. This is a normal transfer - your wallet shows a plain send, with no "deceptive request" warning, because nothing is signed.
We check the transfer on Base and name the exact problem - wrong network, wrong amount, wrong recipient, or not visible yet.
Faster: one signature in your wallet, no copy-paste of a transaction hash. This is the x402 flow - the wallet signs a single transfer authorisation that expires in 5 minutes.
Your wallet may show a security warning
Your wallet may show a “deceptive request” warning - it is a false positive: you sign a transfer of exactly $0.10 USDC to AOTrust, valid for 5 minutes, and no spending allowance is granted. Prefer not to sign at all? Use “Pay by transfer” - a normal send, no signature, no warning.
MetaMask displays "This is a deceptive request" for x402 payments because the recipient address is new. This is normal and expected - you are signing a TransferWithAuthorization for exactly $0.10 USDC to AOTrust (0x97E9…c800). The signature is one-time only, expires in 5 minutes, and cannot be reused. It does not grant unlimited access to your funds.
Safe to confirm. The $0.10 payment goes directly to AOTrust.
This file is already registered
A new registration is a reaffirmation: the same file with a new timestamp and signature - it never outranks the first record and does not replace the existing certificate. Free on the free tier; the paid rail charges its usual price.
Cryptographically Protected
It records what this receipt proves - and how to verify it.
Your file is now cryptographically shielded.
Share the certificate with your client - the record stays public and verifiable.
Same file, two levels of proof.
No wallet, no link to you - it proves when, not whose. Anyone could have anchored it.
The payment confirms the link between the file and the payer.
Notarize the moment you finish - and no one can show an earlier record of your file than yours. Earliest means earliest in this log - public, append-only, verifiable by anyone.
Practical, no jargon - what to do when work is stolen or a client stops paying.
Three steps. No accounts, no subscriptions, no fine print.
Your file stays in your browser - only a SHA-256 hash leaves your device.
One-time micropayment. No subscriptions, no hidden fees. Just your wallet, one click.
Download a Shield Certificate with QR code. Verify on verify.aotrust.link.
Every freelancer has a story like these.
You spent three days on a logo mockup. The client said "we went another direction." Two weeks later, your design is live on their website - with someone else's name on it. A Shield Certificate proves the file existed in your hands first.
You sent a draft article for review. The client "passed" - then published your words under a staff byline. Your draft existed, timestamped and cryptographically signed, before their publication date. That's your leverage.
You shared a code snippet to "show you can do the work." They used your code, shipped the feature, and never hired you. Shielding the file creates an immutable record that ties the work to you - before they ever see it.
You delivered a strategy report as part of a paid engagement. The invoice is still "processing" but your analysis is already in their board deck. Shield your report before sending - so "processing" can't mean "we already used it."
No blind faith required. Here's what backs every Shield Certificate.
Your file is hashed with SHA-256 right in your browser. That hash - a unique fingerprint of your work - is what gets timestamped. Change a single pixel and the hash breaks.
We never see your work. We never store it. We never upload it. Only the SHA-256 hash is sent - and a hash cannot be reversed back into your file. Your intellectual property stays yours.
The payment settles on Base; the receipt itself - your file hash plus your signature - is anchored hourly into AOTrust's cumulative Merkle log on the NEAR blockchain: a public, immutable record that stays verifiable even if this service disappears.
Anyone can verify a Shield Certificate at verify.aotrust.link - no account, no app, no "trust us." The proof speaks for itself. The verification page is open and works on any device with a browser.
Three steps. About five minutes. No prior experience needed.
Add the MetaMask browser extension or mobile app. It's a free, self-custody wallet - you hold the keys, not a bank.
Open MetaMask, switch to the Base network, and use the built-in buy feature to purchase about $2 worth of USDC. That's enough to shield 20 files - plenty of room to try it out.
Come back here, drop your file, and click Shield. MetaMask will ask you to confirm the $0.10 payment. Done - you'll get your PDF certificate in seconds.
Need help? The MetaMask warning you'll see is normal - it's a one-time signature for exactly $0.10. Read the warning box above for details.
Someone sent you a file with a Shield Certificate PDF. Here's how to verify it's authentic.
Scan the QR code on the PDF with your phone camera.
Visit verify.aotrust.link and enter the Shield ID (8 characters, shown on the PDF).
Verification is instant, free, and works on any device. No wallet or account needed.
Straight answers. No jargon.