An enhanced blockchain certification option offered by Tediji
The proliferation of sensitive digital content — creations, R&D work, algorithms, databases, contractual documents — now makes it essential to be able to prove its existence, integrity and precedence over time.
Tediji has established itself as one of the leading players in content certification using blockchain anchoring. While the probative value of this type of evidence is now widely accepted, the difficulty often remains in presenting it in clear and convincing terms before a court.
To address this challenge, Tediji now offers an enhanced legal certification option, combining blockchain timestamping and official certification by a judicial officer, which can be activated on demand according to the client's needs.
This service is operated in partnership with Maître Marc-Aurèle Carucci, judicial officer, vice-president of the National Union of Judicial Officers (UNCJ) and partner at CG2M Paris.
This page presents our new enhanced certification option in detail.
Blockchain timestamping: technical principles
Blockchain timestamping involves recording the cryptographic fingerprint (hash) of a document in a distributed ledger on a given date. This operation allows the existence of a file to be frozen at a specific moment in time and certifies that it has not been modified since.
The hash acts as a unique mathematical signature: any modification, even minimal, to the document results in a different fingerprint. Once anchored in the blockchain, this fingerprint becomes immutable and publicly verifiable.
Compared to traditional mechanisms — deposit with a third party, Soleau envelope, digital safe — blockchain offers several key guarantees:
- immutability of records,
- independent verifiability,
- technical transparency,
- absence of a single central authority,
- temporal traceability.
Legal framework: blockchain and electronic registers
The use of electronic registers is now governed by a European regulatory framework, notably through the eIDAS Regulation, revised in 2024 (‘eIDAS 2.0’), which regulates systems that guarantee data integrity and chronological order.
When a blockchain meets this definition of an electronic register — i.e. a system that stores a sequence of records in a reliable and unalterable order — it can fall within this legal framework.
Several recent court decisions have confirmed the admissibility of this type of evidence. In a counterfeiting case heard in 2025, a French court recognised that a timestamp certificate recorded on the public Bitcoin blockchain could be used to establish the anteriority of a work. The court described this element as ‘prima facie evidence in writing’ within the meaning of the Civil Code and expressly stated that ownership of the rights was demonstrated by blockchain timestamps made prior to the dispute.
The limitations of purely technical evidence
However robust it may be from a cryptographic point of view, blockchain alone does not constitute absolute proof in the legal sense. A transaction recorded in a distributed ledger attests to the existence of a digital fingerprint on a given date, but is not sufficient, in isolation, to characterise all the elements expected in a litigation context.
Its strength depends on its inclusion in a complete legal chain of trust, including the integrity of the source file, the reliability of the anchor date, the identification of the depositor, the contractual context in which the evidence was produced, and the methods used to store the documents.
In isolation, a blockchain transaction therefore remains a technical element. To be fully effective before a judge, it must be placed within a clear and intelligible procedural framework capable of articulating cryptographic elements, factual context and legal guarantees — which is precisely why the intervention of a trusted third party and the implementation of a reinforced certification system are justified.
Presenting evidence in a comprehensible manner before the judge
In practice, presenting blockchain evidence in court poses a major challenge: its readability.
Although French civil law enshrines freedom of evidence and gives judges sole discretion to assess the value of the evidence submitted, magistrates must still be able to evaluate the reliability of the process within a limited time frame, without having in-depth expertise in cryptography.
Presenting a hash, a transaction and a blockchain explorer may not be sufficient. To be truly effective in litigation, technical evidence must be placed within a clear procedural framework that is understandable to the court.
It is precisely to meet this requirement for clarity and evidentiary security that Tediji has designed its enhanced certification offering, based on a structured observation protocol carried out by a judicial officer.
In partnership with the latter, Tediji has set up a system designed to cover the entire chain of evidence: from the filing of the document to its anchoring on the blockchain, including verification of the mathematical reliability of the fingerprint in the event of a dispute.
This finding acts as an interface between technology and the courts: it explains, records and certifies, in legal terms, what the blockchain fingerprint demonstrates. Through this mediation by a ministerial officer, the digital evidence is thus translated into a format that is immediately understandable and usable by the judge, without the need for in-depth technical explanations.
The effectiveness of this approach was particularly evident in its adoption in a recent case, in which the court relied on blockchain timestamps to establish the anteriority and authenticity of documents. This concrete recognition paves the way for increased use of this type of enhanced certification in litigation, without requiring the judge to perform an in-depth technical analysis.
The judicial officer's report: legal basis and probative value
The use of a judicial officer — a profession created from the merger of bailiffs and judicial auctioneers — is now a key practice in strengthening the enforceability of digital evidence.
The official report is an official document drawn up with public faith. In French law, it is considered literal (written) evidence, belonging to the category of so-called ‘perfect’ evidence. The judicial officer reports exclusively what he or she has personally seen and observed.
This particular nature gives the report structured probative force, based on several levels.
On the one hand, the report contains information that is authentic in nature, including the date, location and actions taken by the judicial officer. These elements benefit from a particularly strong presumption and can only be challenged through a procedure for registering forgeries. This quality is decisive in legally establishing a situation at a specific point in time.
On the one hand, the report contains information that is considered authentic, in particular the date, place and actions taken by the judicial officer. These elements are subject to a particularly strong presumption and can only be challenged through a procedure for registering forgeries. This quality is decisive in legally establishing a situation at a specific point in time.
On the other hand, the material findings reported in the report are deemed authentic until proven otherwise: the burden of proof then lies with the person challenging these elements. Although they are not authentic documents in the strict sense, they have quasi-official status, enshrined in particular by Law No. 2010-1609 of 22 December 2010 (known as the ‘Béteille Law’). Their strength lies in their objectivity: they relate to purely material facts observed without interpretation.
Finally, the judicial officer is a sworn lawyer, bound to respect the fundamental principles of the trial, the rights of the defence and individual freedoms, in particular respect for privacy and the home. This ethical requirement guarantees that the operations described in the report are carried out without stratagems or unfair practices.
In the specific context of blockchain timestamping, the report allows technical evidence to be integrated into a complete chain of evidence. In particular, the commissioner can:
- verify the identity of the depositor,
- verify the calculation of the document's digital fingerprint,
- check its anchoring on the blockchain on the announced date,
- compare the corresponding technical data,
- describe the tools used,
- record all of these elements in their report.
By linking the blockchain fingerprint to the identity of the depositor, the date of the operations and their context, the report reinforces the probative value of the evidence.
It thus acts as a trusted third party by recording the technical operation within a documented procedural framework and supplementing the cryptographic evidence with verification, procedural and documentary guarantees that are essential to the exercise of the judge's sovereign discretion.
The Tediji protocol: certification reinforced by official certification
To address the evidentiary challenges associated with sensitive digital content, Tediji has developed an enhanced certification option based on a comprehensive protocol combining blockchain anchoring and the intervention of a judicial officer.
Tediji's certification protocol includes the production of the blockchain evidence itself and, where applicable, the intervention of a judicial officer to secure its use in litigation. It is carried out in the following stages:
- Filing of the document and traceability of the operations carried out,
- Calculation of the digital fingerprint (hash) according to a documented procedure (tools used, technical parameters, reproducibility),
- Anchoring of the fingerprint on a public blockchain,
- Methods of storing evidence (files, metadata, technical evidence),
- Intervention by the judicial officer within a defined scope: verifications and findings,
- Drawing up of the report of findings (if the option is activated),
- Delivery of a legally usable evidence file (cryptographic evidence + legal document, if applicable).
This option is available on request, depending on the customer's needs and use cases (intellectual property, R&D, regulatory compliance, contractual evidence, digital assets, etc.). It can be implemented in two ways:
- In systematic mode, with periodic (e.g., daily) reports covering a set of timestamps made over a given period;
- On demand, which is preferred initially, in which a report is generated specifically for one or more identified documents, particularly in anticipation of or in the context of litigation.
In both cases, the report covers the anchoring operations performed and the associated technical elements, as recorded in the logs, metadata, and evidence retained by Tediji in accordance with its protocol.
Marc-Aurèle Carucci emphasizes:
“Information technology is evolving rapidly, and judicial officers must adapt to it. Blockchain represents a major opportunity for our profession. Tediji is one of these next-generation solutions that can provide digital evidence much more effectively than traditional methods.”
In practical terms, when a document is certified via Tediji, the blockchain proof can be accompanied, upon request, by an official report drawn up by a judicial officer.
The client then has cryptographic proof and a formal legal document, which together constitute a body of evidence that can be used directly in court in the event of a dispute. This makes it easier for a corporate lawyer to present such evidence in court.
By combining the technological power of blockchain with the procedural security of an official report, Tediji transforms blockchain timestamping into legally operational evidence, ready to be produced in court.
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