Hashes before proof
DataStamp computes SHA-256 on device and works with hashes/proof material instead of uploading the original private document as the timestamp payload.
Local-first proof vault
Timestamp evidence without surrendering the evidence.
DataStamp creates portable OpenTimestamps proofs for text, photos, screenshots, contracts, receipts, and files. Hash locally. Anchor to Bitcoin. Keep the original content under your control.
Proof vaultBitcoin anchored
Contract draft.pdf
SHA-256 · 4f7c2a9e8d12...c31b0a77e5
ConfirmedOpenTimestampsBlock 842,913
Research note
Proof pending · original text stored locally
Private iCloud optionalNo account
Receipt photo
Verify .ots proof from Files, Photos, or Share Sheet.
No central account
The app has no proprietary DataStamp account system, analytics backend, advertising network, or tracking service.
Portable verification
Create, monitor, export, and verify OpenTimestamps proofs anchored to Bitcoin using a polished iOS workflow.
Privacy posture
DataStamp is designed for defensible records without a central server. Your records live on your device. If you enable iCloud sync, they sync through your own private iCloud account using Apple's CloudKit infrastructure.
What the app may access
Camera, Photos, and Files are requested only when you choose to timestamp or verify content from those sources. Network access is used for OpenTimestamps calendars and related proof verification endpoints.