Blockchain-verified document integrity

Sign documents with cryptographic proof

Every signature is anchored to the blockchain. Every document has an unbreakable chain of custody. Prove authenticity to anyone, anytime, without trusting a third party.

Immutable Hash Chain

Every action from upload to final signature creates a cryptographic hash chain. Tampering with any step invalidates the entire record.

AI Field Detection

Upload a document and our AI identifies signature zones, date fields, and form areas automatically. Set up signing in seconds, not minutes.

Public Verification

Anyone can verify a signed document against the blockchain record. No account needed. Works even if Zdottedline is offline.