Legal notice
Information about the publisher and host of btc3r.com, consumer mediation, protection of personal data and cookies, in accordance with French Law No 2004-575 of 21 June 2004 on confidence in the digital economy (LCEN), the French Consumer Code and the General Data Protection Regulation (GDPR).
Last updated: July 2026
Site publisher
The btc3r.com website (hereinafter “the Site”) is published by:
DIA-SYSTEM, a French simplified joint-stock company (SAS) with share capital of €16,000,
registered with the Trade and Companies Register under number R.C.S. Paris 384 781 175,
whose registered office is at 58 rue de Monceau, 75008 Paris, France.
Intra-EU VAT number: FR 81 384 781 175.
Contact: contact@btc3r.com or via the Site’s contact form.
Site host
The Site is hosted by:
o2switch, a French simplified joint-stock company (SAS) with share capital of €100,000,
registered with the Clermont-Ferrand Trade and Companies Register under number 510 909 807 (SIRET 510 909 807 00032),
whose registered office is at Chemin des Pardiaux, 63000 Clermont-Ferrand, France,
telephone: +33 4 44 44 60 40.
Telecom operator registered with ARCEP 09/2989 – AS50474.
Site activity
The Site offers a paid service for inscribing data — a plain-text message or a SHA-256 cryptographic fingerprint — onto the Bitcoin blockchain, by means of transactions containing an OP_RETURN output. Prices are shown in euros, all taxes included. The user’s account is topped up via PayPal; each inscription is debited from the balance after the user’s explicit confirmation.
The user is informed, before any inscription, of its public and irreversible nature. btc3r is an independent service, not affiliated with the Bitcoin Foundation or any other organisation related to the Bitcoin protocol.
Intellectual property
All elements making up the Site (texts, graphics, logos, structure, code) are protected by intellectual property law and remain the exclusive property of DIA-SYSTEM or its licensors. Any reproduction, representation or exploitation, in whole or in part, without prior written authorisation, is prohibited and may constitute infringement within the meaning of articles L. 335-2 et seq. of the French Intellectual Property Code.
Content inscribed onto the Bitcoin blockchain by users remains their sole responsibility; the user warrants that they hold the necessary rights over any content they have inscribed.
Consumer mediation
In accordance with articles L. 612-1 et seq. of the French Consumer Code, every consumer has the right to free recourse to a consumer mediator for the amicable resolution of a dispute with a trader, after having first attempted to resolve the dispute directly with that trader by a written complaint.
Any complaint must first be sent to: contact@btc3r.com.
[Details of the consumer mediator to which DIA-SYSTEM has subscribed: name, postal address and website of the mediator — to be completed once membership is effective.]
Protection of personal data
The processing of personal data is governed by Regulation (EU) 2016/679 of 27 April 2016 (GDPR) and by the amended French Data Protection Act No 78-17 of 6 January 1978. The data controller is DIA-SYSTEM, identified in Article 1.
6.1 — Data processed, purposes and retention
| Data | Purpose | Legal basis (art. 6 GDPR) | Retention period |
|---|---|---|---|
| User account: name, email address, password (hashed) | Account creation and management, authentication, email address verification | Performance of the contract | Lifetime of the account, then deletion or anonymisation |
| Billing address (company, address, postal code, city, country) | Issuing invoices | Legal obligation (invoicing) | 10 years (art. L. 123-22 of the French Commercial Code) |
| Account movement history (deposits, debits, inscriptions) | Balance keeping, invoicing, proof of operations | Performance of the contract and legal obligation | 10 years (accounting records) |
| Messages sent via the contact form | Handling requests | Legitimate interest (responding to enquiries) | Time necessary to handle the request |
| Technical logs (logs, IP addresses) | Site security, prevention of abuse and fraud | Legitimate interest (security) | 12 months maximum |
6.2 — Payments
Payments are processed by PayPal (PayPal (Europe) S.à r.l. et Cie, S.C.A., Luxembourg), which acts as data controller for payment data. DIA-SYSTEM neither collects nor stores any bank card data: only the identifier and amount of the PayPal transaction are recorded in order to credit the user’s account. PayPal’s processing of data is described in its own privacy policy.
6.3 — Specificity of blockchain inscriptions: why some data falls outside the right to erasure
The very purpose of the service is the permanent inscription of data onto the Bitcoin blockchain, a public, decentralised ledger replicated across thousands of independent nodes worldwide. By design, data confirmed in a block can no longer be altered or deleted — neither by DIA-SYSTEM, nor by the user, nor by any authority: it is this immutability that underpins the evidential and memorial value of the service.
Consequently, the right to erasure provided for in article 17 of the GDPR cannot, in practice, be exercised over the content of a confirmed inscription. This is why the Site: (1) expressly warns the user, before any inscription, of its public and irreversible nature and broadcasts no transaction without their explicit confirmation; (2) recommends never inscribing personal data in plain text — one’s own or that of third parties — and to that end offers the inscription of a SHA-256 fingerprint, computed in the browser, which reveals nothing of the content; (3) reminds users that they are solely responsible for the content they choose to inscribe.
The user’s rights, on the other hand, apply fully to all data kept in DIA-SYSTEM’s systems (account, billing, history, messages), listed in 6.1.
6.4 — Your rights
In accordance with articles 15 to 21 of the GDPR, you have rights of access, rectification, erasure, restriction of processing, objection and portability regarding data concerning you, within the limits set out in 6.3 for data inscribed on the blockchain. These rights are exercised by email to contact@btc3r.com, providing proof of your identity.
If, after contacting us, you believe your rights are not being respected, you may lodge a complaint with the French Data Protection Authority (CNIL), 3 place de Fontenoy, TSA 80715, 75334 Paris Cedex 07 — www.cnil.fr.
Governing law
This legal notice is governed by French law. Any dispute relating to use of the Site falls, failing amicable resolution or mediation, within the jurisdiction of the competent courts under ordinary law. The consumer retains the benefit of the protective jurisdiction rules provided for by the French Consumer Code and the Code of Civil Procedure.