Privacy Policy
ZKNOT, INC. ("ZKNOT," "we," "us") operates HashStamp. This policy explains what we process and why. HashStamp is offered to US customers only (see Terms).
1. The file never leaves your device
Your file is hashed in your browser. We receive only the SHA-256 fingerprint and any optional public label. We never receive, see, or store your file or its contents, and we cannot reconstruct your file from the fingerprint. We also do not receive your file's name for new records.
Do not assume "the file never leaves your browser" means we process no personal data. We do process the categories below.
2. What we collect, and why
| Category | What | Why | Where |
|---|---|---|---|
| Email address | If you buy Founding Supporter Status (collected by Stripe) or join the reserve list | Send your receipt; contact reserve-list subscribers; recover access by email | Stripe; our Cloudflare KV store |
| Payment information | Card details and billing info | Process payment | Stripe only — we never receive or store card numbers |
| Payment metadata | Amount, currency, Stripe session/payment identifiers, order reference, timestamps | Record and reconcile your purchase | Our Cloudflare KV store |
| File fingerprint (SHA-256) + timestamp + chain linkage | The committed record you create | Provide the verifiable record | ZKNOT chain database; public on the verifier; cryptographically committed and permanent |
| Optional public label | Free text you choose to attach to the record | Let you identify the record publicly | ZKNOT chain database; public on the verifier; display metadata — not part of the cryptographic commitment |
| Coarse location + device string | Approximate country (from your IP) and, for reserve signups, your browser's User-Agent | Anti-abuse; US-only screening; ops notice | Our Cloudflare KV store |
| Network/technical | Your IP address is used transiently to rate-limit requests | Prevent abuse | Not stored by us in application data; may appear in infrastructure logs |
We do not collect your file, your file's contents, or (for new records) your filename.
3. Public information — what is permanent, and what is not
The file fingerprint, timestamp, service signature, chain position, and any public label you enter are published and are verifiable by anyone. They do not all behave the same way.
Committed fields — permanent. The fingerprint, timestamp, and chain linkage are cryptographically committed to a tamper-evident, hash-linked chain. They cannot be edited or deleted; doing so would defeat verification.
The public label — published, but not committed. Your label is separate display metadata. It is published and intended to persist, but it is not covered by the record's cryptographic commitment, and we retain discretion to stop displaying, suppress, or redact it (see Terms §7). Suppressing a label does not alter the committed fingerprint or timestamp. We do not promise label removal on request.
Do not put confidential or personal information in a public label. (See Section 5 for deletion requests and their limits.)
4. Who we share data with (processors)
- Stripe, Inc. — payment processing (card data, email, billing). Stripe's own privacy policy governs data you enter on its checkout page.
- Cloudflare, Inc. — hosting, the Worker, Pages, the KV store, and edge request logs (which may include IP address and requested path).
- Resend — sends your receipt email and our internal notifications; receives recipient email address and message content.
- Railway — hosts the ZKNOT chain database where records are stored.
Our pages load no third-party resources: fonts are served from our own domain, and the site embeds no advertising or analytics beacons.
We do not sell your personal information.
5. Retention, deletion, and your choices
How to request deletion. Email [email protected] from the address associated with your purchase or reserve signup, or include your order reference. We will delete the personal data we hold about you — your email address and associated purchase and reserve records — within 30 days of verifying your request. This is a manual, human-handled process; we do not offer a self-service deletion tool today.
What we can delete: your email address and the purchase/reserve records that contain it, from our systems.
What we cannot delete, and why:
- Committed chain fields — the file fingerprint, timestamp, and chain linkage — are cryptographically committed to a tamper-evident, hash-linked chain and are permanent by design; they cannot be deleted without defeating verification. (The file fingerprint is a one-way hash from which your file cannot be reconstructed and which contains no name, email, or address.)
- Public labels are display metadata rather than committed fields, so they are not subject to that same technical permanence. We nonetheless do not offer label removal as a right, and we ask you never to put personal or confidential information in a label. If you believe a label exposes personal data, contact [email protected]; we will consider suppression case by case under Terms §7, but cannot guarantee an outcome.
- Payment records held by our payment processor (Stripe) are retained as required for tax, accounting, and fraud-prevention purposes and are governed by Stripe's own terms.
We will confirm when your deletion request is complete.
Retention otherwise: we keep account, purchase, and reserve data for as long as needed to provide the service and meet legal and accounting obligations, and then delete or de-identify it. You may unsubscribe from the reserve list at any time.
6. Logging
We keep operational logs to run the service reliably. Our application logs are written to avoid recording payer email addresses. Infrastructure and edge logs (Cloudflare, our host) may record IP addresses and request paths.
7. Conversion and advertising tracking
When active, HashStamp will use advertising and conversion-measurement technologies (for example, the Meta pixel and/or Google Ads conversion tags) that set cookies or similar identifiers and share limited event data (such as page views and completed purchases) with those platforms to measure and improve advertising. At that time we will provide a cookie/consent notice describing these technologies and your choices, and this section will take effect.
8. Contact
ZKNOT, INC., PO Box 993, Salt Lake City, UT 84110, USA · [email protected]