A file can be copied. A file can be edited. A database can be changed. A server can disappear.
How can you prove what a digital artifact looked like at a particular point in time?
Bob says this is the original contract.
Alice says Bob added a zero. Can we prove who is right?
A cryptographic hash (SHA-256) is a digital fingerprint. Try changing Bob's bonus.
A change to the input produces a different SHA-256 digest with overwhelming cryptographic probability. SHA-256 is designed to make finding a collision computationally infeasible. If the bytes change, the fingerprint changes entirely.
What if we have 1,000,000 contracts? We pair their hashes up and hash them together until only one Root Hash remains.
Change one file, and only its path to the root changes.
A Merkle proof demonstrates that a particular leaf belongs to a committed Merkle tree. Instead of providing the entire dataset, the verifier only needs the leaf hash, the sibling hashes along the path, and the expected root. For a balanced tree containing N leaves, the proof requires only O(log N) hashes.
This architecture avoids putting the original document or its contents on-chain, reducing data-retention and privacy risks.
The evidence is committed to a blockchain transaction included in a block with a recorded timestamp. The blockchain acts as a public, decentralized time-stamping authority. We don't prove when the file was created; we prove that this exact content had been committed to the blockchain by the time of the anchor.
We prepared a real, mathematically valid P2P agreement on the TON Testnet. Fetch the cryptographic manifest via API, or download the ZIP for 100% offline verification.
ProofCore is an evidence engine for anyone needing cryptographic proof of digital artifacts. Common use cases include:
Create tamper-evident records of digital forensics. Prevent counterparties from secretly editing trade signals or wiping agreements. Forward once to anchor permanently.
Freelance contracts, OTC deals, and milestones acknowledged by two Telegram accounts and cryptographically committed to a tamper-evident proof record.
Secure critical business correspondence. ProofCore preserves and verifies the email's DKIM authentication, linking the message to its signing domain.
Archive pricing pages, government registries, or controversial web statements. Captures full-page DOM and embeds the target server's SSL certificate fingerprint.
Establish cryptographic evidence of prior existence for source code, designs, audio tracks, and patent drafts without uploading confidential files to the public blockchain.
Attest LLM security audits, GitHub release binaries, and agent-to-agent decisions to make supply-chain vulnerabilities and hallucination disputes auditable.
ProofCore strictly adheres to a Zero-Storage on Blockchain policy. Your original files, images, or documents are never uploaded to the public TON ledger — only the 64-character cryptographic hash (Merkle Root) is anchored.
Why do we retain files off-chain?
proofcore-merkle-v1GET https://api.proofcore.org/api/v0.1/proof/{uuid}H_asset = SHA256(raw_bytes)H_deal = SHA256((H_assets + H_meta).encode('utf-8'))direction == 'left' ? SHA256(0x01 ‖ sibling ‖ current) : SHA256(0x01 ‖ current ‖ sibling)MR: <64-char-root>