Vincent
Software engineer. Designs the product, from the security model to software development.
Who builds Seedcase, and why.
An independent team in Bordeaux, France, with one conviction: don't harden the point of failure, remove it.
Why a seed needs a case.
It's called a seed phrase for a reason: everything you own grows from it. In nature, a seed doesn't survive by being locked away. Its case lets it scatter, stay sealed, wait, and open only when the conditions are right. That is the case we build.
Your seed phrase is the seed.
Seedcase, its protection.
Scatter.
Seeds don't stay in one place, they scatter so they last.
Fragments go to different places and different people. A fire reaches one of them, not all.
Seal.
While the case is intact, the core remains inaccessible.
A fragment on its own reveals nothing about your seed phrase. That isn't a promise about trust. Below the threshold, the information is absent, not hidden.
Wait.
Some seeds lie dormant for decades, until their season comes.
Fragments sit offline and stay readable even if Seedcase is gone.
Open.
A seed opens only when the conditions are right.
Your seed phrase is only revealed when enough fragments are brought together: the threshold you chose.
The people behind it.
Engineers, brought together around one problem: keeping a seed phrase safe, recoverable and transmissible, without anyone ever taking control of it.
Thomas
Connects Seedcase to trusted professionals: partners, wealth advisors and notaries.
Supported by
Talk to us
A question, a partnership, a setup you want to think through. Write to us: [email protected]
The principles that guide us.
Your funds are out of our reach.
Seedcase never holds your seed phrase, or enough fragments to rebuild it. That isn't a promise: it's a technical constraint. Read the security model
Standards, not a Seedcase format.
Fragments follow SLIP-39, a public standard built on Shamir's Secret Sharing, a scheme studied since 1979. We don't invent cryptography, and any compliant tool can combine what we produce. Read the SLIP-39 specification
We say what isn't done yet.
The independent audit is planned, not done. The NFC card is still in development. Pricing isn't settled. You'll read it here before you find out somewhere else.
Built with the people who use it.
The beta is in the hands of people who manage real seed phrases. What they report decides what we build next, and in what order. Join the beta
Where we are, and what's next.
Seedcase is in private beta. We move one stage at a time.
Done
Foundations
- Frag-ment, the first version of the app, in 2025.
- Cryptographic core open source.
- Supported by Bordeaux Technowest and La French Tech.
Now
Private beta
- Desktop app on Windows, macOS and Ubuntu.
- Mobile vault on Android.
- Testers who manage real seed phrases, setting what ships next.
Next
Audit, then V1
- Independent security audit.
- Full report published.
- Mobile vault on iOS.
- V1 stable release.
Later
NFC and succession
- EAL5+ NFC card.
- Succession workflows for families, advisors and notaries.