Here's a scenario every creator has faced: you need to prove your work exists, but you don't want to hand it over to someone else in the process.
Registering a script with a guild means giving them a copy. Filing with the Copyright Office means submitting your work. Sharing with a lawyer means someone else has your manuscript. Every traditional method of protection requires you to hand your creative work to a third party.
ProofChain doesn't. And this isn't a marketing feature — it's a fundamental architectural decision with real implications for your creative security.
What "Zero-Knowledge" Means
In cryptography, zero-knowledge refers to a class of proofs where one party can prove a fact to another party without revealing any information beyond the fact itself.
In ProofChain's case: we can prove your file existed at a specific time without ever seeing, reading, accessing, or storing your file.
How is this possible? SHA-256 hashing.
How It Works
When you use ProofChain, here's what happens on your device:
Your file is processed locally. The SHA-256 algorithm runs on your device — your computer, your phone, your tablet. The file is read by the algorithm, converted into a unique 64-character hash, and the process completes entirely within your device.
Only the hash leaves your device. The 64-character hash string is sent to ProofChain's servers. This hash is a one-way mathematical transformation — it's computationally impossible to reconstruct your file from its hash. Sending us the hash tells us nothing about what your file contains.
The hash gets timestamped. ProofChain records the hash on the blockchain and obtains a TSA certificate. These records prove that this specific hash existed at this specific time.
Your file stays with you. At no point does your screenplay, your song, your manuscript, your legal document, or any other file touch ProofChain's servers. We never see it. We never store it. We couldn't access it even if we wanted to.
Why This Matters for Creators
Your unpublished work stays unpublished. When you register a work with traditional services, you're creating a copy that exists on someone else's system. If that system is breached, your unpublished work could be exposed. With ProofChain, there's nothing to breach — your work exists only where you put it.
Confidential material stays confidential. Legal documents, NDAs, contracts, business plans — these often contain sensitive information. Timestamping them shouldn't require sharing their contents with a third party.
You control distribution. As a creator, controlling who sees your work and when is part of your creative and business strategy. Sending an unpublished screenplay to a timestamping service is an unnecessary distribution point. With zero-knowledge architecture, you add zero distribution points.
There's no insider risk. Employees at traditional registration services theoretically have access to submitted works. This isn't a theoretical concern — content leaks happen. ProofChain eliminates this risk entirely because there's no content to leak.
The Hash: Your File's Unique Fingerprint
Let's go deeper into why the hash is sufficient proof without the file.
SHA-256 produces a fixed-length 64-character hexadecimal string regardless of input size. A 1-page poem and a 500-page manuscript both produce 64-character hashes. But those hashes are completely different and completely unique.
The properties that make SHA-256 suitable for this purpose:
Deterministic. The same file always produces the same hash. If you hash your screenplay today and hash the exact same file next year, you'll get the same result. This means you can always connect your file to its timestamp.
Collision resistant. Finding two different files that produce the same hash is, with current technology, impossible. The probability is approximately 1 in 2^256 — a number with 77 digits. Your hash is effectively unique to your file.
Pre-image resistant. Given a hash, it's computationally infeasible to determine what file produced it. This is why sending ProofChain your hash reveals nothing about your file's contents.
Avalanche effect. Changing a single bit in your file completely changes the hash. Adding a comma, changing a word, modifying a note — any alteration produces a hash that bears no resemblance to the original. This means your timestamp is specific to the exact version of your file.
Verification: Proving the Connection
When you need to prove your work existed at a specific time, here's how verification works:
- 1You present your original file
- 2Anyone can hash the file using SHA-256
- 3The resulting hash is compared to the hash recorded on the blockchain and in the TSA certificate
- 4If they match, it's mathematically proven that this exact file existed at the recorded time
This verification can be performed by anyone — a court, a lawyer, an independent expert — without needing ProofChain's involvement. The blockchain is public. The TSA certificate is independently verifiable. The SHA-256 algorithm is open and standardised.
What ProofChain Can't Do (By Design)
Because of our zero-knowledge architecture:
We can't recover your file. If you lose your original file, we can't help you get it back. We never had it. This is why we emphasise keeping your originals safe.
We can't view your content. We don't know whether you timestamped a screenplay, a song, a contract, or a shopping list. All we see is a hash.
We can't share your work. Even under legal compulsion, we can't produce your files because we don't have them. We can confirm that a hash was timestamped at a specific time — that's all.
We can't modify your timestamp. Once the hash is on the blockchain and in the TSA certificate, neither we nor anyone else can alter it. The records are immutable.
These aren't limitations — they're features. They mean that using ProofChain introduces zero additional risk to your creative work's confidentiality.
Comparing to Traditional Methods
| Aspect | Traditional Registration | ProofChain |
|---|---|---|
| File access by service | Yes (they store your work) | No (hash only) |
| Risk of content leak | Non-zero | Zero |
| Insider access risk | Yes | No |
| File recovery if you lose yours | Possibly (they have a copy) | No (you must keep originals) |
| Independence from service | Limited (their records, their systems) | Full (blockchain is public, TSA is independent) |
| Speed of registration | Days to months | Minutes |
| Privacy of unpublished work | Compromised (exists on their servers) | Preserved (never leaves your device) |
The Creator's Responsibility
Zero-knowledge architecture shifts one responsibility to you: keeping your original files safe.
Your ProofChain timestamp proves that a file with a specific hash existed at a specific time. To use that proof, you need to produce the original file so its hash can be verified against the timestamp.
This means:
- Back up your files. Use multiple storage locations — external drives, cloud storage, offline backups
- Don't modify originals. Any change, however small, changes the hash. Keep timestamped versions untouched
- Organise by version. When you timestamp multiple drafts, keep each version clearly labelled and linked to its corresponding timestamp certificate
- Store certificates alongside files. Your ProofChain certificate should be stored alongside the file it corresponds to
The Bottom Line
Protection shouldn't require exposure. You shouldn't have to risk your creative work to prove it exists.
Zero-knowledge timestamping resolves this contradiction. It gives you proof without requiring disclosure. It creates evidence without creating vulnerability. It protects your work by never touching it.
Your file. Your device. Your proof. Nobody else needs access.