Evidence
Create a Private Proof-of-Existence Record
Select any file — a design, a manuscript, a codebase archive, an invention description — and get a dated certificate of its SHA-256 fingerprint. The calculation happens in your browser: the file never leaves your device, which is exactly why this is private.
How it works
A SHA-256 hash is a 64-character fingerprint computed from a file's exact bytes. Change one pixel or one comma and the fingerprint changes completely; keep the file identical and anyone, on any computer, can recompute the identical fingerprint decades later. Your certificate records the fingerprint and the generation time — so if a dispute ever asks "did this file exist in this form by that date?", you can produce the unchanged file and let anyone verify the match.
The honest limitation: the certificate proves the fingerprint was generated at a time, not who authored the file. Keep the original file safe and unchanged — the certificate is worthless without it. For stronger, independent date evidence, professional options exist; ask a professional what fits your situation.
Why "the file never leaves your device" matters
An unpublished invention or manuscript is often most valuable while it is secret. Uploading it to any website — including ours — creates a copy outside your control. This tool reads the file locally, computes the hash locally, and transmits nothing: no upload, no logging, no analytics on the file or its name. You can verify this yourself — open your browser's developer tools (Network tab) while using the tool and watch: no network request carries your file.
Idea Vault FAQ
Evidence questions, answered plainly
Protecting the idea itself?
A hash preserves evidence; it does not create rights. For patents, designs and registrations, talk to MYCrave about what your idea actually needs.
Does this give me a priority date for a patent?
No. Patent priority comes from filing a patent application. This record can support other evidence about when a document existed, but it is not a filing and creates no patent rights.
What file types and sizes work?
Any file type — the hash works on raw bytes. Large files work too; the tool hashes in streaming chunks, so even multi-GB files process without loading everything into memory, though very large files take a while. If your browser struggles, try zipping the content first.
Should I hash each file or one ZIP?
Both are valid. One ZIP of a whole project is convenient; individual hashes let you later prove one file without revealing the rest. If in doubt, do both and keep everything.
How do I verify the hash later?
Recompute SHA-256 over the same unchanged file — with this tool, or offline (certutil -hashfile file SHA256 on Windows, shasum -a 256 file on macOS/Linux) — and compare it with the certificate. The certificate itself explains this.