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HashMyWords guide

How to show something existed at a certain time

A practical approach: preserve the content, fingerprint it, timestamp the fingerprint and keep enough information to verify it later.

Choose a proof workflowLearn how it works

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Start with the exact material you want to preserve

The first step is deciding what you actually need to prove existed. For text, that means keeping the exact wording. For any digital material, small changes matter: an extra space, punctuation change or edited line can create a different cryptographic fingerprint.

Keep an original copy in a stable place before you create the timestamp.

A simple four-part method

Preserve the originalSave the exact text or file state you care about. Do not rely on memory or a later reconstruction.
Create a cryptographic fingerprintUse SHA-256 so the precise content can be represented by a fixed-length hash.
Timestamp the fingerprintRecord that fingerprint through a system with an independently verifiable time record, such as Hedera.
Keep the receipt and contextStore the receipt, secret code, original material and any surrounding records that explain where the material came from.

Why a normal file date is not enough

A computer's “created” or “modified” date is useful for everyday organisation, but it is generally controlled by the device or filesystem. It can change when files are copied, restored or edited, and it is not an independent public record.

A ledger timestamp is different because the relevant transaction is recorded by an external network. That does not make it proof of authorship, but it creates a stronger independent reference point for the fingerprint.

How to verify the evidence later

Verification is a comparison exercise. Take the material you want to verify, recreate its fingerprint using the same method and compare that value with the earlier recorded fingerprint. If the values match, the material you have now is consistent with the content represented by the timestamped record.

HashMyWords also gives each submission a secret code so you can confirm that the code matches the one-way verifier stored with that HashMyWords record.

Common mistakes to avoid

  • Losing the original content. A timestamped hash cannot recreate the words for you.
  • Losing a private receipt. Private submissions need receipt information to recreate the salted hash.
  • Assuming a timestamp proves identity. It records a fingerprint, not a person's identity.
  • Editing the material after timestamping. The edited version will normally have a different hash.
  • Relying on one technical record for a complex dispute. Preserve surrounding evidence too.

Frequently asked questions

Can a timestamp prove I had an idea first?

It can help show that matching recorded content existed by a particular time. Whether that proves priority, authorship or legal rights depends on the wider evidence and applicable law.

What if I change one word after timestamping?

The changed text will normally produce a different SHA-256 hash, so it will not match the earlier fingerprint exactly.

Should I timestamp confidential material publicly?

Not if you want the plaintext to stay private. Use Private text mode, which keeps the plaintext and salt in your browser and records only the resulting salted hash.

Is the Hedera timestamp the same as my computer clock?

No. The proof is confirmed by the Hedera network, giving you an external ledger record rather than a date controlled only by your own device.

Continue in the Guide

Protect a PDF before AIHarden and timestamp a PDF before uploading it to ChatGPT, Claude, Gemini, Microsoft Copilot or another AI tool.Proof of existenceLearn how digital proof of existence works and create a verifiable timestamp that can help show matching content existed by a certain time.Timestamp text onlineTimestamp text online for free. Create a verifiable Hedera record of your words and keep a secret code so you can verify the same text later.Hedera timestampingLearn how cryptographic timestamping works, what a proof hash can demonstrate, and how HashMyWords records proof hashes through Hedera Consensus Service.SHA-256 hashingLearn how SHA-256 hashing works, when to use it and why exact bytes matter. Then open the HashMyWords browser-based hash generator to calculate hashes locally.
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