For years, developers have worked on expanding Bitcoin’s use case beyond being a transaction ledger. What if, for instance, whenever you signed a contract –  for starting a new job, for signing on to a service or for closing on a house – you could use the Bitcoin blockchain to publish legally binding, immutable proof of the contract and your signature to it? 

Woleet is a French startup whose business model revolves around this very application. A DocuSign of sorts that uses Bitcoin, the project has been quietly building for four years. Woleet debuted a front end last month, having sold application programming interfaces (API) for its software for the past few years.

“With Woleet Sign we plan to demonstrate our ability to address electronic signatures with the same level of user experience as the traditional actors in this space. The software-as-a-service application will help us to promote our highly customizable API for signature workflows in various business applications,” Gilles Cardignan, the CEO of Woleet, told CoinDesk.

Woleet: Notary meets Bitcoin

Woleet provides a software suite that allows its clients to authenticate documents and signatures using Bitcoin’s blockchain. Anyone needing to authenticate this data can verify these proofs using hashes that correspond to the signatory and the document’s public key.

These proofs can be used as timestamps, electronic signatures, electronic seals and digital IDs. 

Read more: Microsoft Releases Bitcoin-Based ID Tool as COVID-19 ‘Passports’ Draw Criticism

Woleet does not handle customer data; on the backend, it sends transactions to the Bitcoin blockchain to hash proofs for clients, but the documents never leave the client’s local computer or server storage unless it opts for cloud storage through a provider like Google. 

This model is a notable exception to traditional e-signature services, which store documents and other data for their clients. With Woleet, clients can use its self-hosted ID server to manage digital identities and key pairs for their documents and signers.

According to its website, Woleet is compliant with the European Union’s General Data Protection Regulations (GDPR), and its signatures are legally binding.

The service already has a growing list of clients including luxury goods company Kering, renewable energy providers EDF and Acciona and pharmaceutical lab Servier, among others.

“At first we were seen as an innovation startup only good for proof of concept, like all the other ‘enterprise blockchain’ technologies available.” Cardigan said. “Today, the fact that big companies trust us is helping a lot to sell to medium-sized companies with the same needs for certification and electronic signatures.”

Self-sovereign digital IDs on Bitcoin

With its launch, Woleet joins a class of Bitcoin startups working to bring self-sovereign digital identities to the fore of Bitcoin’s enterprise applications.

The Microsoft-incubated ION project, for instance, is creating a platform for issuing what it calls Decentralized Digital IDs (DDIDs) on Bitcoin. 

The RGB protocol, which entered beta this summer, could also provide a platform to create similarly decentralized and digital IDs, among a slew of other applications.

Read more: Self-Sovereign Identity Explained

At their core, the difference between these identity systems and their legacy counterparts comes from their “sovereign” nature. Their users would store the data that is being authenticated themselves rather than relinquishing it to a third party. Bitcoin’s blockchain provides an immutable record for the data proofs, eliminating another layer of third-party trust from the process.