PROXAE

Use case

Alternative to the Soleau envelope

The Soleau envelope was discontinued by France's INPI in 2020. To prove the priority of a creation without sending the document, Proxae offers an instant, free, and permanent alternative anchored in the Bitcoin blockchain.

The Soleau envelope was long the go-to method for proving prior art. But it costs €15, takes weeks, and expires after 5 years. Proxae offers the same service — instantly, for free, and forever.

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Limitations of the Soleau envelope

€15 per submission, 2 to 4 weeks processing time, limited to 5 years of storage (renewable once), and most importantly: you must send your document to INPI, breaking confidentiality. Furthermore, INPI discontinued the service in 2020.

Who needs a Soleau alternative?

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An industrial designer who used to certify plans via Soleau envelope and needs a digital replacement since its discontinuation.

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An author who wants to timestamp a manuscript before sending it to a publisher — with no cost or delay.

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An SME documenting internal innovations to build a priority proof portfolio at minimal cost.

How Proxae replaces the Soleau envelope

1

Upload your file or text

The SHA-256 fingerprint is computed locally. Your document never leaves your device — total confidentiality.

2

Instant blockchain anchoring

No need to wait for postal mail: the timestamp is submitted to the Bitcoin blockchain in seconds.

3

Permanent preservation

Unlike the Soleau envelope (5 years), your proof is anchored in Bitcoin forever. No renewal, no expiration.

The Soleau envelope no longer exists. Proxae replaces it — better, faster, and free.

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Proxae vs Soleau envelope vs e-Soleau

Proxae Soleau envelope e-Soleau (INPI)
Cost ✓ Free €15 €15
Speed ✓ Instant 2-4 weeks A few days
Privacy ✓ Full (local hash) Document sent File uploaded
Permanence ✓ Permanent (Bitcoin) 5 years (renewable 1×) 5 years (renewable 1×)

Proxae vs Soleau envelope

  • ✦ Free instead of €15 per submission
  • ✦ Instant instead of 2 to 4 weeks
  • ✦ Permanent instead of 5 renewable years
  • ✦ Private — your document is never transmitted

Frequently asked questions

Does the Soleau envelope still exist?
INPI discontinued the Soleau envelope in 2020, replacing it with the e-Soleau service. Proxae is a blockchain-based alternative independent of any institution.
Does Proxae have the same legal value?
Proxae provides verifiable timestamped proof of existence. With the Pro plan, the eIDAS-compliant RFC 3161 certificate strengthens admissibility. It is a complementary piece of evidence, not a property title.
Can I certify the same types of documents?
Yes — text, files, source code, designs, and even URLs. Anything that can be hashed can be certified.
What is the difference between Proxae and e-Soleau?
e-Soleau is the digital successor to the Soleau envelope, managed by France's INPI. It costs €15, stores for 5 years, and requires uploading the file. Proxae is free, permanent, and never stores your document.
Is Proxae timestamping recognized in court?
Blockchain timestamping is admissible evidence in court. The RFC 3161 certificate (Pro plan) complies with the eIDAS regulation, strengthening its probative value in the European Union.
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The modern alternative to the Soleau envelope.