Legal-grade proof of existence on Bitcoin, OpenTimestamps, and Sigstore Rekor. Certify any digital file in seconds — immutable, independently verifiable.
Proof options
Start with free instant proofs. Upgrade to Bitcoin when you need permanent on-chain anchoring.
OpenTimestamps + RFC 3161 TSA + Sigstore Rekor in one certificate.
Bitcoin-backed calendar stamp. Upgrades to on-chain proof over time.
Public transparency log entry with cryptographic attestation.
Permanent OP_RETURN anchor on Bitcoin mainnet. Uses plan quota.
Free proofs (Maximum, OTS, Rekor) don't count toward your monthly Bitcoin quota. See pricing →
The challenge
Ideas get challenged. Authorship is questioned. Documentation is often missing.
Platform
From first draft to court-ready evidence — one platform, multiple proof layers.
Files encrypted in your browser before upload. Not even mltio can read them.
Choose Bitcoin, OpenTimestamps, Rekor, or all three combined — instant free options included.
Court-ready certificates with hash, proof details, block data, and QR verification.
Chain certificates as your IP evolves. Build an unbreakable timeline.
Share with access controls, view limits, expiry, and instant revocation.
Invite team members. Manage shared projects and certificates together.
How it works
Drop any file. Hashed locally — content never leaves your device in hash mode.
Pick Maximum proof (free), individual OTS/Rekor, or Bitcoin blockchain.
Proofs created in seconds. Bitcoin anchors confirm in ~10 minutes.
PDF + evidence pack. Independently verifiable forever.
Use cases
“Blockchain can certainly be used in the context of tamper-proof documentation bearing a precise date and time… platforms are available from established providers.”
— WIPO White Paper on Blockchain and IP (2022)
Get started
Maximum proof free instantly. Bitcoin certificates on paid plans. No credit card required.