This article aims to study how a technology
decentralised becomes a legal certification tool.
“Between technical promise and
legal framework in construction”
Contents
I – Introduction: Blockchain, a new tool for proof
II – How does blockchain proof work?
III – The benefits of Blockchain: speed, cost, decentralisation
IV – Where do we stand worldwide? Chronological landmarks
V – The case of France: cautious recognition
VI – The current limits of blockchain proof
VII – Conclusion
I – BLOCKCHAIN AS A NEW TOOL OF PROOF
The blockchain is often associated with cryptocurrencies, but it conceals a promising legal use: lthe certification of digital evidence.
Day after day, she is gaining formal legal status in the world's major economies.
Before going into the technical and legal details, one simple idea must be borne in mind: blockchain makes it possible to prove that a digital file existed, in a precise form, at a given time.
This is what is known as «blockchain proof» — a tool that could transform the way we establish the prior existence of a creation, the authorship of a work or the existence of a trade secret.
Key Points
Blockchain proof is a cryptographic proof that a specific digital file existed in a specific form at a precise moment in time.
II – HOW DOES BLOCKCHAIN PROOF WORK?
The mechanism relies on three steps easy to understand, even without technical knowledge:
Step 1 — The digital fingerprint (the «hash»)
Every digital file (document, photo, video or audio recording, contract, etc.) has a unique fingerprint called a «hash». This fingerprint, calculated by a cryptographic algorithm, is like an irreversible signature: it uniquely identifies a file. Changing a single character in the file completely changes the hash.
Step 2 — Blockchain anchoring
This fingerprint is recorded («anchored») on an immutable public register — the blockchain. Once recorded, it can neither be modified nor erased. Here, the blockchain acts as a public ledger, open to all, which cannot be falsified.
Step 3 — Independent verification
Anyone can, at any time, recalculate a file's fingerprint and compare it to the one anchored on the blockchain. If they match, the document has not been altered since certification. No one else is needed: the proof is self-verifying.
Simple idea
Think of the blockchain as an unalterable public time-stamping machine: you record the fingerprint of a document on it, and anyone can verify that it hasn't changed since.
III – THE ADVANTAGES OF BLOCKCHAIN: SPEED, COST, DECENTRALISATION
Compared to traditional proof tools, blockchain certification presents three major assets :
– She is Instantaneousno appointments to make, no registration delays. We certify in a few seconds.
– She is Affordable the cost is negligible compared to a notarised deposit or copyright registration.
– She is Verifiable everywhere the evidence can be viewed and verified by anyone, from anywhere.
– She is Decentralised it does not depend on any single institution. It is anchored on an infrastructure that persists independently of any company or government.
In an intellectual property dispute, this makes it possible to establish prior art, establish creation dates, document a trade secret and demonstrate the evolution of a work — all with mathematical certainty.
IV – WHERE DOES THE WORLD STAND? CHRONOLOGICAL LANDMARKS
The legal recognition of blockchain evidence is progressing country by country. Here is an overview of the key milestones, tracing two major stages in the evolution of digital evidence law on an international scale. They illustrate how legal systems have had to adapt to authenticate electronic data reliably and swiftly.
A/ December 2017 [UNITED STATES]: The self-authentication rule (FRE 902)
Amendments to Rules 902(13) and 902(14) of the US Federal Rules of Evidence (FRE) have profoundly changed the management of electronic evidence in court:
Before the amendment: To admit a file or computer data in court, it was often necessary to have an expert or technician testify at the hearing (a forensic expert) to guarantee that the file had not been altered.
Following the amendment: Records generated by an electronic process or copied from a digital medium become self-authenticating.
The role of the hash: To be eligible, the evidence must be accompanied by a written certificate drawn up by a qualified person.
This is where the cryptographic hash comes into play.
If the file’s current «hash» matches exactly the «hash» generated when it was captured or created, the court considers that the integrity of the evidence has been mathematically proven. Oral testimony from an expert is no longer required.
B/ June 2018 [CHINA]: The first blockchain-based judgment (Hangzhou Internet Court)
On 28 June 2018, the Hangzhou Cyberspace Court (the city is home to the Alibaba Group’s headquarters, amongst other things) handed down a landmark ruling on intellectual property:
The case (Huatai v. Daotong) : A media company (Huatai) accused a third party of plagiarising and publishing its content online without authorisation.
Innovation: To prove that copyright had been infringed at the exact time the events took place, the victim had the source code and screenshots of the infringing web pages recorded on a blockchain.
The decision: The Hangzhou Internet Court became the first court in the world to officially recognise blockchain as a legal and admissible tool for securing, preserving and retrieving tamper-proof electronic evidence. A few months later, the Supreme People’s Court of China extended this rule to the whole country.
C/ February 2019 [ITALY]: One of the first pieces of national legislation to grant full legal validity to blockchain-based timestamping.
Italian Law 12/2019 (and specifically Article 8-ter thereof) marked a major turning point in Europe by becoming one of the first pieces of national legislation to grant full legal validity to blockchain-based time-stamping, thereby bringing it into line with the standards of the European eIDAS Regulation.
Here are the key points to help you better understand the scope of this law:
D/ LEGAL FRAMEWORK AND EQUIVALENCE
Legal equivalence: A time stamp on a distributed ledger (blockchain) has the same legal effect as a conventional electronic time stamp under European law.
Proof of time: It provides legally binding proof of the exact date and time at which a document or piece of data was entered into the register.
Inviolability: The law recognises the decentralised, immutable and transparent nature of the technology as a guarantee that data cannot be altered.
E/ CONTEXT & IMPACT IN EUROPE
A pioneer in Europe: By enacting this legislation as early as February 2019, Italy has positioned itself at the forefront of regulatory innovation relating to Web3 and distributed ledger technologies (DLT).
Interoperability: This law anticipated subsequent European developments (such as discussions around eIDAS 2.0) aimed at harmonising the recognition of blockchain-based trust services across the European Union.
V – THE CASE OF FRANCE: A CAUTIOUS APPROACH
Under French law, whilst any form of evidence is, in principle, admissible in civil or commercial matters, the admissibility of blockchain evidence is still subject to the rule of imperfect evidence, subject to traceability and certified signature requirements specific to electronic documents.
A/ A CASE-BY-CASE ASSESSMENT
Freedom of evidence: In civil cases, there are no restrictions on the admissibility of evidence. A judge cannot reject a blockchain entry simply because it is in digital form.
The judge’s assessment: Blockchain is imperfect evidence. The court assesses its probative value in the light of the other evidence in the case.
Recent developments: Rulings, such as that handed down by the Marseille Judicial Court in 2025, accept blockchain timestamping as proof of the prior existence of a creation, without automatically validating it. You can read a detailed analysis of these developments on the Village de la Justice website.
This «hesitant approach» adopted by French law is summed up in two illustrative decisions:
1 – March 2025 [FRANCE] Recognition of the validity of a blockchain timestamp as proof of prior copyright.
On 20 March 2025, the Judicial Court of Marseille [Judicial Court of Marseille, 1st Civil Chamber, 20 March 2025, Docket No: 23/00046] recognised for the first time in France and in Europe the validity of a blockchain timestamp to prove the prior existence of copyright.
a/ The facts
The dispute: The case pitted the famous fashion house AZ Factory against the company Valeria Moda for clothing counterfeiting
The proof: To establish that she was indeed the origin of the designs before her competitor, the brand produced a digital timestamp certificate anchored to a public blockchain.
b/ The scope of the decision
A recognised first: The judges have accepted that the time-stamped digital fingerprint constitutes an admissible and probative means of proof in intellectual property matters.
A necessary addition: The court did not single out the blockchain as the sole absolute evidence. It forms part of a body of evidence (combined with other elements such as publications or official reports) to attest to the integrity of the creation on a specific date.
A revolution for creators: This case law offers a modern and cost-effective alternative to traditional filings (Soleau envelope, bailiff) to establish the existence of an intangible work.
2 August 2025 [FRANCE] the Briey Court rejects a DocuSign signature
Judicial Court of Val-de-Briey, Judge for the Enforcement of Protection Measures, 5 August 2025, Docket No.: 25/00115
Conversely, this court strictly rejects a DocuSign signature, illustrating the caution that still surrounds certain forms of electronic evidence.
The contrast with Marseille's decision highlights a rapidly evolving body of case law.
The opposition between the rejection of a DocuSign signature and the favourable reception of blockchain reveal the evolution of digital evidence law in France
Issue to note
It is not disputed that blockchain offers numerous guarantees regarding document integrity. However, certain obstacles still prevent it from being granted greater evidentiary value.
VI – CURRENT LIMITATIONS OF BLOCKCHAIN PROOF
If blockchain is a excellent machine for freezing time and the state of a file, it is unable to judge the relevance or legitimacy of what he is given to record.
blockchain proof stumbles upon two major difficulties :
Author traceability: The identity of the person certifying a document can easily be masked or substituted. The blockchain proves that the document existed, but does not definitively prove who deposited it.
Document quality: The certification of a false document is not excluded. Blockchain guarantees the integrity of a file from its anchoring, but does not verify the veracity of its content at the time of submission.
VI – CONCLUSION
These limitations explain why blockchain proof alone is not always enough.
They are paving the way for a hybrid approach combining several devices.
The analysis of emerging validity criteria explores the opportunity of an approach combining:
Commercial electronic signature — to identify the author; ;
Blockchain timestamping — to date and ensure integrity; ;
Involvement of a trusted third party — to provide institutional backing.
This combination could become a new standard for securing banking transactions and, more broadly, digital legal documents.
To be continued!
