01
Fingerprint
Your file is hashed into a unique fingerprint. Change a single byte and the fingerprint changes completely.
report.pdf → oRhIy+IJ…95eD8=
Proof of existence · anchored on XRP & Solana
Your digital
notary.
Fingerprint any file, anchor it on a public blockchain, and get a certificate anyone can check, without having to trust us. Free.
SHA-256 fingerprint
computed in your browser, the file never leaves it
XRP Ledger Solana
Only the fingerprint leaves your deviceThree steps from file to proof.
Nothing to install, no account required. The certificate you get back is all you need to prove your file later.
02
Anchor
The fingerprint joins a Merkle tree whose root is written to the XRP Ledger and/or Solana: public, decentralized, permanent.
merkle root → tx on XRP · Solana
03
Verify
Anyone holding the file and its certificate can confirm it existed at that moment, and hasn't been altered since.
file + certificate → ✓ unchanged
Trust no one, including us
Verification doesn't need cronStamp.
Each certificate carries the Merkle path and the blockchain transaction it points to. Checking it happens entirely on your side, against the public ledger, so your proof keeps working whether or not our servers do.
document hashoRhIy+IJ…95eD8=
merkle path4 nodes
root on ledgerpfE98QsU…cDd8w=
result roots match
When “it was like this” has to hold up.
Start stamping →Copyright protection
Defend your intellectual property with an undeniable proof of originality.
Auditing & compliance
Timestamp critical records so regulators and auditors can verify them independently.
News & publishing
Prove an article hasn't been quietly edited after it went live.
Data storage integrity
Detect unauthorized changes to files kept in the cloud or on third-party storage.
Creator originality
Show you made it first: drafts, designs, code and recordings alike.
Surveillance & access logs
Make footage and access records tamper-evident from the moment they're captured.
For developers
Stamp from your own pipeline.
Timestamp strings, files or raw hashes with the JavaScript client library or the Web API, and verify locally, in Node or the browser.
$ npm install @cronstamp/clientlib
Read the developer docs →stamp.ts
import { requestCertificateForString, verifyCertificateForString } from '@cronstamp/clientlib';
// anchor on the XRP Ledger
const result = await requestCertificateForString(message, ['xrp'])
.onMessage((data) => console.log(data.message))
.start();
// later: runs fully client-side
const check = await verifyCertificateForString(result.currentCert, message).start();Questions, answered.
Anything else? Get in touch or read how it works in detail.
Do you see or store my file?
No. Your file is hashed (SHA-256) in your browser and only that fingerprint is sent to cronStamp. The fingerprint does not reveal anything about the content.
How long does it take?
On the XRP Ledger your fingerprint is anchored within a minute. Solana is anchored twice a day, so a certificate including Solana can take up to about 12 hours.
What happens if cronStamp shuts down?
Your proof keeps working. The certificate contains everything needed to check it against the public blockchain, and the check runs locally with the client library, in any browser or Node.js.
What exactly does a certificate prove?
That this exact file existed at the time of the blockchain transaction and has not changed since. It does not prove who created the file or what it means.
Does it cost anything?
No. Stamping and verifying are free and need no account.