How a file becomes proof.
SIGIL is plumbing for ownership. Every work you publish passes through a deterministic pipeline that produces signals three different audiences can verify: humans, search engines, and the automated rights systems run by social platforms.
Five layers of evidence
Each layer is independently checkable. Together they make “who owns this?” a question with one answer.
We hash the exact bytes of your file. The hash is unique to that image — change a single pixel and it changes completely. It’s the cryptographic anchor every other record points to.
→The same hash, computed anywhere in the world, proves a file is byte-for-byte your registered original.
A second, “fuzzy” fingerprint derived from the image’s structure. Unlike SHA-256, it survives resizing, cropping and re-compression — the things platforms do to every upload — so a scaled-down re-post still resolves to your work.
→Detects near-duplicates and re-uploads that an exact hash would miss.
We write your copyright notice, creator credit, licence, usage terms and a link back to your registry page directly into the image, using the IPTC Photo Metadata and Adobe XMP standards. These are the exact fields Meta, Google and stock systems surface as “Photographer / Credit / Copyright.”
→A crawler reading the file alone already knows who owns it and where to verify.
Your public proof page emits an ImageObject / CreativeWork graph with copyrightHolder, copyrightNotice, creator.sameAs (your FB/IG/TikTok), licence and acquireLicensePage. This is what powers Google’s “Licensable” badge and what rights bots parse.
→Machines get the claim in a structured, unambiguous form — not scraped from prose.
Every registration writes an append-only ledger entry, each one hashed together with the previous. Edit a past record and the chain visibly breaks. Your display date is editable; the underlying proof timestamp is not.
→Tamper-evidence: the order and integrity of your claims can be checked, not just trusted.
Built for the reviewer that isn’t a person.
When a platform’s automated system encounters your image, it doesn’t read your bio. It reads the file and the page. SIGIL makes sure both speak in the formats those systems already understand.
Our robots.txt and headers explicitly welcome facebookexternalhit, Instagram, TikTok’s Bytespider, Twitterbot and search crawlers, and every proof page is public — no login wall between a bot and your claim.
The Web Statement of Rights embedded in each image links back to its registry page. A bot can follow it and confirm the metadata matches the source.
creator.sameAs lists your verified Facebook, Instagram and TikTok URLs, tying the work to the same identity those platforms already know.
Each work carries a registry number, hashes and an immutable timestamp — exactly the evidence a copyright or takedown report asks for.
Boring, durable, yours.
No proprietary cloud. Runs entirely on the LAMP/XAMPP stack you already have, so your registry can’t be switched off by someone else.