Proof of existence vs proof of authorship
A blockchain timestamp proves that a specific file existed at a specific moment and has not changed since. It does not prove who created that file. The distinction matters, and anyone selling you blockchain timestamping as "proof of authorship" is overselling it.
The short answer
Blockchain timestamping proves existence, not authorship.
A timestamp is a cryptographic fact about a file: this exact sequence of bytes existed no later than this block. It says nothing about who produced those bytes. If you copy someone else's manuscript and timestamp it, the blockchain will faithfully record that you had a copy on that date — and nothing more.
That is not a flaw. It is what the tool is for. The confusion comes from marketing that blurs the two.
What each one actually means
| Proof of existence | Proof of authorship | |
|---|---|---|
| What it establishes | A file existed by a date, unaltered since | A specific person created the work |
| How it is established | A cryptographic hash anchored in a public ledger | Evidence about a person and a process |
| Who can verify it | Anyone, independently, forever | A court, weighing the whole record |
| Can it be faked | No — the ledger is append-only and public | Yes, in principle, by a determined liar |
| Cost | Cents to a few dollars | Registration fees, or litigation |
| What it is worth alone | Strong, narrow, objective evidence | The thing you ultimately need to win |
Why a timestamp still matters for authorship
Authorship is rarely proven by one artefact. It is proven by an accumulation of consistent evidence, and a timestamp is unusually good evidence for one specific part of it: priority.
If you can show that your version existed on 3 March and the other party's first appearance was in July, you have shifted the burden. The other side now has to explain how they independently produced the same work, or how they had access to yours. That is a much harder position to argue from.
What makes the timestamp persuasive is not that it names you. It is that:
- It is objective. Nobody, including the service that issued it, can backdate a block that is already mined.
- It is independent. Verification does not depend on the issuer still existing, or on their honesty.
- It is precise. A hash matches or it does not; there is no interpretation.
What actually proves authorship
Combine the timestamp with things that connect you to the work:
- A trail of drafts. Timestamp early and often — outlines, first drafts, working files. A sequence of dated versions that visibly evolve into the final work is very hard to fabricate after the fact, and almost impossible for a copier to produce.
- Working files, not just outputs. The layered PSD, the project file, the raw footage, the LaTeX source. A copier usually has only the exported result.
- Registration where it exists. In the US, copyright registration creates a public record and is required before you can sue. It is the legal heavyweight; a timestamp does not replace it.
- Ordinary contemporaneous evidence. Emails, commits, messages to collaborators, invoices, briefs. Boring, dated, and corroborating.
The strongest position is a dated chain of your own working process, anchored so the dates cannot be disputed.
The honest limits
Be clear-eyed about what a timestamp cannot do:
- It cannot prove you wrote the file, only that you had it.
- It cannot prove the work is original rather than derived from something older.
- It proves the file existed no later than the block. It says nothing about how much earlier it existed.
- It does not create any legal right. Copyright arises when you fix the work in tangible form, with or without a timestamp.
Anyone claiming a blockchain record establishes authorship on its own is either confused or selling something.
Why this is the right trade
The reason timestamping is useful despite this limit is the cost asymmetry. Registration costs a fee per work and takes time, so people register finished work — occasionally. Timestamping costs almost nothing and takes minutes, so you can do it continuously, on every draft, from the first outline.
That continuity is what generates the evidence that actually matters. One timestamp on a finished file is weak. Forty timestamps tracing a work from a rough outline to a final cut is a story only the real author can tell.
In practice
- Timestamp the earliest version you have, today.
- Timestamp again at meaningful milestones, and keep every certificate.
- Keep the original files unchanged — any edit changes the hash and breaks the link.
- Register the finished works you might actually defend.
- Treat the timestamp as the dated spine of your evidence, not the whole case.
See how verification works for the mechanics, or proof of existence for what the record itself contains.