School project for Softcom Technologies SA
Registered mail, tracked on a blockchain
A proof of concept for Softcom Technologies: every delivery of a digital document is recorded on a blockchain, from sending to receipt.
A proof of concept commissioned by Softcom Technologies SA, in Givisiez, as part of a school project. I built it with my friend Maxime Genilloud.
The brief
Define a use case, pick the right technologies, then build a web application that records the delivery of digital documents on a blockchain: who sends, to whom, which document, and where the delivery stands.
How it works
The document itself never goes through the blockchain. It is uploaded to E-Sign, an existing cloud service for secure document storage, which identifies it by a fingerprint (a hash). That fingerprint is what travels:
- The sender uploads the document to E-Sign.
- E-Sign returns the hash that gives access to the document.
- The sender logs into the web app and sends that hash to the recipient.
- The transaction for this delivery is recorded on the blockchain.
- The recipient logs in and sees a document has arrived.
- The state of the delivery is updated on the blockchain.
Who did what
I developed the smart contract with Hyperledger Composer and the application back-end in .NET Core. Maxime took care of the front-end, in Angular.
Composer generates a REST server from the blockchain’s business model: that is how the back-end reads and writes transactions on Hyperledger Fabric. User accounts live in a regular database.
