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LEGAL ENGINEERING / INFORMATION

Verifying the Statement

How to check that the published document is the one notarized in 2020.

The document

The Statement is the formal definition of Legal Engineering, released under the CC BY 4.0 licence: legal-engineering-statement.pdf (PDF, 391 KB).

SHA-256 fingerprint of the file:
513caa4ec41bbb5acaba9144737425b7b78f92de8e0cf82b5039bad39110f715

The 2020 notarization on Quadrans

On 11 July 2020 at 12:07:09 the document’s fingerprint was recorded on the Quadrans blockchain through the Quadrans Notarize service. Since 2026 the Quadrans verification page can no longer be reached, so we keep the data of the original receipt here, also as a JSON file.

Document fingerprint513caa4ec41bbb5acaba9144737425b7b78f92de8e0cf82b5039bad39110f715
Owner email fingerprint06da5cb0a3bd50ecc1bffbb21e99bd263a6c62ff0d12260caa5006f205a034f5
Recorded evidence (Merkle root)016da1138f2ba94fb7b7bb37ccd915846c62fb1f995437b28e95ed3b48733c2d
Block date and time11 July 2020, 12:07:09

The evidence is SHA-256 applied twice to the two fingerprints joined together: anyone can recompute it and compare it with the recorded value.

The Bitcoin anchor with OpenTimestamps

On 2 November 2026 the fingerprints of the document and of the Quadrans receipt were anchored on the Bitcoin blockchain with OpenTimestamps, an open standard that can be verified without relying on any single provider. The proof shows the files existed at least from that date; the 2020 date remains documented by the Quadrans receipt.

Proof files: legal-engineering-statement.pdf.ots · legal-engineering-statement.quadrans-2020.json.ots

How to verify

  1. Download the PDF and compute its SHA-256 fingerprint: certutil -hashfile legal-engineering-statement.pdf SHA256 on Windows, shasum -a 256 legal-engineering-statement.pdf on macOS and Linux. The result must match the fingerprint above.
  2. Recompute the Quadrans evidence, for example with Python:
    python -c "import hashlib;b=bytes.fromhex('513caa4ec41bbb5acaba9144737425b7b78f92de8e0cf82b5039bad39110f71506da5cb0a3bd50ecc1bffbb21e99bd263a6c62ff0d12260caa5006f205a034f5');print(hashlib.sha256(hashlib.sha256(b).digest()).hexdigest())"
    The result must be 016da1138f2ba94fb7b7bb37ccd915846c62fb1f995437b28e95ed3b48733c2d.
  3. Open opentimestamps.org and drop the PDF together with its .ots file: the site checks the Bitcoin anchor.