Legal admissibility notes
Math a court can verify. Claims a lawyer can defend.
This page explains what a LeoLog proof technically demonstrates, which evidentiary frameworks it is designed to align with, and — because your counsel will ask — exactly what no timestamp, ours included, can ever do.
What a LeoLog proof demonstrates
When you seal an entry, your device computes a SHA-256 fingerprint of the exact content. That fingerprint is batched into a Merkle tree whose root is anchored in a transaction on Base (an Ethereum L2) and, via OpenTimestamps, committed to the Bitcoin blockchain. The resulting proof bundle demonstrates one precise fact: data with this exact fingerprint existed at or before the anchored time. Any alteration of the content — one character, one pixel — produces a different fingerprint and fails verification.
The demonstration is independent of LeoLog: the bundle contains the fingerprint, the Merkle path, transaction identifiers, and timestamp receipts, and it can be replayed at verify.leolog.io — which recomputes everything client-side against public chain data — or by any OpenTimestamps-compatible tool, with no LeoLog account and no LeoLog server.
Frameworks this design aligns with
- United States — FRE 902(13) and 902(14): the self-authentication rules for records generated by an electronic process and for data copies verified by hash values. LeoLog proofs are built to support certification under exactly these mechanics — a documented process whose output is checked by hash comparison.
- European Union — eIDAS (as updated by eIDAS 2.0): electronic timestamps enjoy non-discrimination as evidence — they cannot be denied legal effect solely for being electronic — and the regulation contemplates ledger-based records.
- Italy — D.L. 135/2018, Art. 8-ter: among the first statutes to give distributed-ledger timestamping the legal effect of an electronic time validation.
- China — Internet Court practice: the Supreme People's Court has recognized blockchain-fixed evidence in the Internet Courts since 2018, subject to technical verification of the kind LeoLog bundles are built for.
What no timestamp can do
- It cannot guarantee admission or weight. Admissibility is decided by the tribunal, under its rules, on the facts of the case. No provider can promise a court will admit anything, and you should treat any provider who does as a red flag.
- Existence is not inventorship. An anchor proves the content existed at a time. It does not by itself prove you created it, own it, that it is novel or patentable, or that you have priority over any particular party. It is one piece of evidence — often a very useful one — in arguments about those questions.
- A timestamp is not a patent. LeoLog complements, and does not replace, patent filings, trade-secret programs, and confidentiality agreements.
Practical notes for counsel
Each entry exports a typeset certificate (PDF) and a machine-readable JSON proof bundle containing the entry fingerprint, Merkle inclusion path, chain identifiers, transaction hash, block data, and OpenTimestamps receipt. Verification requires only public blockchain data and open-source tooling; the process is documented and repeatable, which is precisely what declarations under FRE 902(13)/(14) — or their analogues elsewhere — want to describe. The underlying content remains encrypted and in the client's control; the proof discloses the fingerprint and timing metadata only, so verification does not require disclosing the invention itself.
LeoLog and Mutagenic Labs, LLC are not a law firm and this page is not legal advice; it describes our technology and the public legal landscape as we understand it. Evidentiary questions are fact- and jurisdiction-specific — consult your own IP and evidence counsel. The operative legal terms are the Terms of Service, §5 of which governs proof-related representations.