The Pigi envelope allows you to upload and retrieve files to and from the Bitcoin blockchain. The files are encrypted by default and allow any user with access to the reference and encryption secret to access the original file and check its authenticity.
Below the process is shown in a schematic overview.
A popular use case is distribution and storage of authenticated digital files, linked to physical documents. The digital document is often linked using a QR code, containing the reference and secret. Users can scan the QR code to fetch the digital document, or processes can be put in place to automatically recognize the reference and secret on the physical document in order to fetch an authenticated and augmented digital document from the blockchain. Recipients can easily verify that the document has not changed in the meantime.