Boxcryptor is a flexible and scalable encryption software for the cloud, that supports more than 30 providers (including OneDrive, SharePoint and an integration in Microsoft Teams) as well as NAS encryption on all platforms. It offers collaboration, audit, and management features that allow secure collaboration on files while being compliant with privacy regulations. Thanks to zero knowledge encryption, all company data is securely protected from third-party access.

BlockchainSign is a blockchain timestamping service for people holding documents they cannot hand over.

Conventional options all require custody: a copyright office wants a deposit copy, a notary wants to see the paper, an e-signature platform wants the file on its servers. BlockchainSign never receives the file at all. The document is hashed with SHA-256 in the user's own browser using the Web Crypto API, and only the resulting hash is written to the Ethereum blockchain.

The result is a certificate file recording the hash, the transaction and the timestamp. Because each certificate is its own Ethereum L1 transaction, with the payload hash readable as UTF-8 on a public block explorer, verification does not run through the vendor's portal: if BlockchainSign shut down, existing certificates would still verify.

There is no subscription and no cryptocurrency wallet involved. Certificates are bought as credits with a card and spent when needed. Credits are valid for 12 months; an issued certificate never expires.

Key points

• The file is never uploaded — only its SHA-256 hash is transmitted
• Recorded on Ethereum L1, one transaction per certificate
• Verifiable on a public block explorer, independently of us
• No subscription, no renewal, no wallet, no crypto knowledge needed
• A free SHA-256 file hash generator is available with no account
• Available in English, French, German, Spanish and Portuguese

What it does not do. A timestamp proves that a file existed in that exact form at that time — existence and integrity. It does not prove authorship or ownership, and it is not a substitute for copyright registration. There is no API or integrations yet, and no eIDAS qualified timestamp.