How to create and use a proof
A vDPO Proof helps you preserve an exact version of a document or file and retrieve independent evidence of when its digital fingerprint was recorded.
Choose the final version
Select the exact policy, contract, assessment, report, investigation record or other material you need to preserve.
Create the proof
vDPO creates a digital fingerprint (SHA-256 hash) of the file in your browser. Your file stays private: only the fingerprint is recorded, on the Arc Blockchain.
Keep the complete record
Download the certificate and evidence package. Store them with the original file, its fingerprint and any internal note explaining the record's purpose, owner and retention period.
Verify when required
Paste the recorded fingerprint or select the original file. vDPO recreates the fingerprint on your device and opens the matching public proof record.
Blockchain Evidence
Blockchain records can strengthen evidence of integrity and chronology because the fingerprint and its record can be checked independently. Courts and legislation still consider how the source material was collected, preserved and connected to the parties.
Hangzhou Huatai v Shenzhen Daotong
The Hangzhou Internet Court examined webpage capture evidence anchored through Factom and Bitcoin. Its assessment considered the source, collection method, generation and transmission path, technical checks and supporting evidence.
China: Blockchain-preserved evidence
Chinese courts have accepted Blockchain as a method of preserving and checking electronic evidence, while continuing to assess whether the collection, creation and preservation process was reliable.
United States: Vermont law
Qualifying Blockchain records may be self-authenticating under Vermont law and may support presumptions about authenticity, recording time and attribution when the statutory conditions are met.
European Union: eIDAS timestamps
An electronic timestamp cannot be refused legal effect or admissibility merely because it is electronic. Qualified timestamps receive stronger presumptions concerning recorded time and data integrity.
United States: federal evidence rules
Blockchain records can be presented using existing electronic-evidence and authentication rules, supported where appropriate by system evidence, digital identification, certifications, business records or expert testimony.
India: Bharatiya Sakshya Adhiniyam, 2023
Sections 61 and 63 address electronic records and their admissibility. The prescribed certificate includes the electronic record's hash value, making cryptographic hashing directly relevant to the evidentiary process.
Adapted from the BlockchainProof overview of Blockchain evidence.
Evidence Package
Keep the downloaded package with the original material. Together, these records allow the proof to be checked later without exposing the source file publicly.
Proof record
A file listing the fingerprint, the time it was recorded and where it is recorded on the Arc Blockchain.
Independent check
Technical details anyone can use to confirm the record directly on the Blockchain, without relying on vDPO.
Blockchain record
The transaction ID and a link to the public Arc Blockchain explorer, where anyone can see the record.
Certificate
A printable certificate summarising the record and explaining how to verify it.
Original file stored with the archive
Keep the original file privately. Its fingerprint can be recreated later and matched against the proof record.