Create mathematical proofs of anything you see online

Prove what you see online and share it with anyone. No screenshots, no PDFs, no forgery. Every website becomes a universal API for verifiable data.

How it works

Documents can be faked. Proofs can't.

Blind Witness uses zero-knowledge TLS to turn anything visible in your browser into a mathematical proof, backed by the website's own certificate.

For the first time, anyone can verify with absolute certainty what appeared on any website, at any moment. No trust required. No intermediaries. This unlocks a universal layer of truth for the internet: verifiable income for lending, provable credentials without paperwork, tamper-proof records for legal disputes, and countless applications that aren't possible when proof depends on screenshots, PDFs, and notarized documents that anyone can fabricate.

01

Browse any website

Visit any HTTPS site as you normally would. Blind Witness participates in the TLS handshake without ever seeing your data.

02

Click to witness

Select any element on the page: a balance, a message, a status. A cryptographic attestation is captured from the server's real certificate.

03

Share verifiable proof

Get a compact zero-knowledge proof that reveals only what you choose. Anyone can verify it. No one can forge it.

A new web of trust

Blind Witness is one unified API for everything you want verified and notarized, turning every website into a verifiable data source. Proof flows freely between services without needing integration.

Balance: $284kB.S. Computer Science1,247 contributions"Offer: $150k accepted"Portfolio: $47.2kEmployed at Stripehttps://chase.comhttps://zillow.comhttps://linkedin.comhttps://github.comhttps://mit.eduhttps://slack.comhttps://robinhood.comhttps://airbnb.com

Today, proving something from one service to another requires custom API integrations, data-sharing agreements, and months of engineering on both sides. A lender verifying your bank balance, an employer confirming a degree, a landlord checking your income: each one needs its own pipeline, and most don't exist. So people fall back on screenshots, PDFs, and notarized documents that anyone can fabricate.

Blind Witness eliminates this entirely. It works within the encrypted connection your browser already uses on every website. Through a multi-party computation during the TLS handshake, the session key is split so that no single party, including Blind Witness, ever sees your data in full. A zero-knowledge proof is then generated that lets you share only the specific detail you choose, like a balance or a job title, while keeping everything else private. The recipient can verify it came directly from the website's own certificate, not from you.

The result is that any information visible in a browser can be cryptographically proven and shared with anyone: a mortgage lender, a court, a business partner, an insurer. No cooperation from the source website required. No new integrations to build. The entire web becomes an open network of verifiable data.

The forgery crisis

AI can fake any document.
It can't fake math.

Generative AI now produces flawless utility bills for proof of address, pay stubs for rental applications, insurance cards for gig work, and corporate filings for vendor onboarding, in seconds, at zero cost. Banks, lenders, landlords, and procurement teams are scrambling to deploy AI-powered detection vendors to keep up. It's an arms race that defenders are structurally set up to lose.

Proof of address · KYC, banking, leases

Today's response is to fight AI with AI: pile on identity vendors and document-forensics platforms that score whether something looks suspicious. It works until it doesn't, because every defensive model becomes a training target for the next generative one. As one banking executive recently put it, fraud detection is now an "ongoing investment, not a solved problem." The cost of producing a convincing fake is approaching zero. The cost of catching one keeps climbing.

Blind Witness ends the arms race rather than escalating it. Instead of guessing whether a document is real, the recipient runs a single cryptographic check against the source website's own TLS certificate. There is nothing to detect, nothing to dispute, and nothing for a generative model to fabricate around. A Blind Witness proof cannot be faked by a better model. Forging one would require breaking the same cryptography that secures every HTTPS connection on the internet.

The internet forgets. Your proof doesn't.

Websites change constantly. Product listings get quietly edited. Terms of service are rewritten overnight. Social media posts are deleted. Prices go up and the old quote disappears. In every one of these cases, the person who needed that information loses their only evidence the moment the page updates.

A Blind Witness proof is locked to the exact moment it was captured. It includes a cryptographic commitment to the content, the timestamp, and the website's TLS certificate at that point in time. Even if the site changes, edits, or takes down the page entirely, your proof remains mathematically valid. No one can dispute what the page said, because the proof is bound to the server's own signature.

Think of it as a notary for the entire internet, running 24/7, that costs nothing and is impossible to forge. Every proof is a permanent, timestamped record that holds up no matter what happens to the original source.

One proof. Every jurisdiction.

A bank in Dubai needs to verify a startup in Thailand before extending credit. Today that means correspondent banks, document chains, and weeks of back-and-forth. With Blind Witness, the startup can prove its registration, revenue, and bank balance directly from Thai portals, and the proof holds the same mathematical validity in Dubai as it does in Bangkok.

A payment platform onboarding thousands of merchants across dozens of countries can verify each one against local registries and bank portals without building integrations into every system. When a transaction moves from bank A through an app to bank C across three jurisdictions, each party can independently prove the exact amount at each step, so disputes have a tamper-proof audit trail instead of conflicting records.

No cross-border data transfer is required. Only the proof travels, and it reveals nothing beyond the specific claim being made.

See it in action

This interactive example shows how simple it is to create a verifiable proof. Click the Witness button, then click any highlighted element to generate one. No technical knowledge required. Blind Witness can be customized to fit any use case. Visit the documentation to learn how to integrate it into your own workflows.

northbank.com/login
engineering
Private channel · shipping updates
14 members
April 18, 2026
James Cooper10:42 AM
Final review on the auth rewrite — shipping Monday if staging stays green.
Sarah Mitchell10:44 AM
On it. Runbook and rollback doc will be ready by EOD.
Mike Reynolds11:09 AM
Just confirmed: Acme signed the enterprise agreement. $420K ARR, 3-year term.
Tom Bradley11:11 AM
That's our biggest deal of the quarter. Great work everyone.
James Cooper11:15 AM
Pushing the release to Tuesday. I want Acme's account provisioned before we go live.
Message #engineering
AR
Portfolio value
$147,832.19
+2.24%+$3,241.07 today
4 assetsEnhanced KYCSince Jun 2021
AssetBalancePrice24h
Bitcoin
BTC
$88,214.50
1.4238 BTC
$61,961.82
+1.8%
Ξ
Ethereum
ETH
$47,584.68
18.92 ETH
$2,515.04
+3.2%
Solana
SOL
$12,033.01
85.00 SOL
$141.57
−0.4%
$
USD Coin
USDC
$0.00
0.00 USDC
$1.00
0.0%
Infinite use cases
Switch tabs with Toggle witness with WClose modal with Esc
Generating proof
zk-TLS · bn254 · Poseidon-256
Copied
Understanding zkTLS

From the HTTPS lock
to verifiable proof

You already trust the padlock in your browser. Blind Witness builds on that same foundation to let you prove what any website showed you, mathematically, privately, and permanently.

The foundation

You already trust the lock

Every time you see the padlock icon in your browser, you're using TLS, the "S" in HTTPS. It creates an encrypted tunnel between your browser and the website, and the website's certificate proves it is who it claims to be.

This is how the entire internet establishes trust today. Your bank, your email, your social media. They all rely on TLS certificates to prove their authenticity to your browser.

https://northbank.com
Connection is secure
TLS 1.3 · Certificate verified · Encrypted
The problem

But you can't prove what you saw

TLS proves the website's identity to you, but it doesn't help you prove to anyone else what that website showed you. Screenshots can be edited. Screen recordings can be faked. There's no way to mathematically prove to a third party what a website displayed to you. Until now.

Forgeable
Screenshots
Screen recordings
PDFs
Notarized printouts
Verifiable
Blind Witness proof
The innovation

Blind Witness sits alongside your connection

During a TLS session, a Blind Witness notary participates in the cryptographic handshake. It can verify that data genuinely came from a specific server, authenticated by that server's real certificate, without ever seeing the plaintext content of the page.

The notary is "blind" to what you're viewing, but it can still mathematically confirm that the data is authentic and untampered.

Your BrowserClient
Blind WitnessNotary
WebsiteServer
The cryptography

Zero-knowledge proofs seal the deal

The notary produces a cryptographic attestation of the data. You can then generate a zero-knowledge proof that selectively reveals only the information you want to share while keeping everything else completely private.

Want to prove your bank balance? You can do that without revealing your account number, transaction history, or any other detail. The math guarantees that the revealed data is genuine.

Account balance: $284,391.27
The result

A proof anyone can verify

The final output is a compact proof certificate. It states exactly what data was observed, which website it came from, when it was captured, and that it was verified by the website's own TLS certificate. Anyone can verify it. No one can forge it.

Verified
Account holderAna Reyes
DataAccount balance: $284,391.27
Sourcenorthbank.com
Timestamp2026-04-21T09:14:00Z
CertificateTLS · northbank.com
ProofGroth16 · 224 bytes

Use cases

Blind Witness works anywhere HTTPS does. Here are just a few examples.

For finance
Balance: $284,391.07
chase.com
A freelancer applying for a mortgage can prove their balance directly from the bank portal instead of downloading and uploading monthly statements that are out of date by the time they arrive.
Revenue: $1.2M TTM
stripe.com
A startup raising a round can prove trailing revenue to an investor from their payment processor during a pitch, skipping weeks of back-and-forth over financials in a data room.
EUR/USD: 1.0847 @ 14:32 UTC
bloomberg.com
In a cross-border trade dispute, both parties can agree on the exact exchange rate at the moment of the transaction instead of arguing over which rate applies.
Payout: $18,400.00 settled
stripe.com
A vendor can prove they received payment to release goods immediately instead of waiting days for the buyer's bank to issue a confirmation letter.
Portfolio: $310,247.83
schwab.com
An individual applying for a margin loan or private credit facility can prove total asset value without handing over months of brokerage statements showing every trade.
Loan: Paid in full, $0 remaining
sofi.com
A borrower can prove a prior loan is fully paid off when applying for new credit, replacing the weeks it takes to get an official payoff letter mailed.
and many more...
For individuals
Status: Active, Software Engineer
rippling.com
A renter can prove their employment status to a landlord directly from their HR portal. Today this means asking HR to write a letter, which can take days and some companies won't do.
Degree: B.S. Computer Science
mit.edu
A job applicant can prove their degree from the university portal. Currently employers either trust a resume or pay for a background check that takes 1-2 weeks.
"The offer is $150k base + equity"
slack.com
In a contract or employment dispute, you can prove what was actually said in a message. Screenshots are routinely thrown out or challenged because they are trivial to fabricate.
Policy: Active, Full Coverage
geico.com
A rideshare driver can prove active insurance coverage to the platform instantly instead of uploading photos of their insurance card, which can be expired or forged.
@username · 12.4k followers
x.com
A creator negotiating a brand deal can prove their real follower count and account ownership. Brands currently have no way to verify these numbers besides taking screenshots at face value.
Reservation: Confirmed, May 12
airbnb.com
A visa applicant can prove they have accommodation booked abroad. Embassies currently accept printed confirmation emails, which anyone can fabricate in a text editor.
and many more...
For businesses
SOC 2 Type II: Compliant
vanta.com
During an enterprise sales cycle, a prospect asks for your SOC 2 report. Instead of emailing a 90-page PDF that might be from last quarter, you share a live proof of current compliance status.
Uptime: 99.97%, P95: 42ms
datadoghq.com
A client claims you violated your SLA. You can prove your actual uptime and latency directly from your monitoring dashboard instead of relying on your own self-reported status page, which they don't trust.
Shipment #TK-7891: Delivered
flexport.com
In trade finance, payment is often held until delivery is confirmed. A supplier can prove delivery status from the logistics portal to release payment, instead of waiting for manual confirmation from multiple parties.
"Price: $49.99/mo" on 03/14
competitor.com
A company can prove a competitor's publicly listed pricing at a specific date for a price-matching clause or antitrust filing. Today this requires notarized screenshots or a forensic examiner.
Terms v4.2, Section 8.1
vendor-saas.com
In a contract dispute, you can prove what a SaaS vendor's terms of service actually said on the date you signed up. Companies change their terms constantly and don't keep public archives.
Listing: "Lead-free, built 2021"
supplier-catalog.com
A manufacturer can prove what a supplier's product listing claimed at the time of purchase for a product liability or warranty dispute. Suppliers can quietly edit listings after the fact.
and many more...
Blind Witness

Upgrade your proof of anything online

Stop relying on screenshots and PDFs that anyone can fake. Start creating mathematically verified, tamper-proof attestations backed by the website's own certificate.