ipfs-market

Example repository intended to demonstrate a simple digital goods trading system powered by Ethereum smart contracts, IPFS file system and some basic cryptography algorithms.

Specifically, the system distinguishes two actors, the publisher and the purchaser. Going down to the use cases:

• A publisher can:

  • publish an encrypted file to the IPFS file system and put it on sale using an Ethereum smart contract

  • watch incoming purchase requests, answer them and withdraw the payment after successful purchases

• A purchaser can:

  • purchase a file using their IPFS content identifier (CID)

Technically, there are several major parts:

• An off-chain CLI application which can operate in different modes (publish, watch and purchase) to handle the use cases of both actors. It is responsible for encryption and decryption of the files and interacts with the Ethereum chain and the IPFS file system.

• An Ethereum smart contract which manages all purchase transactions and acts as an escrow for funds

• The IPFS file system which stores the encrypted files in a distributed manner

Prerequisites

Make sure you have the following prerequisites installed on your machine:

• Go 1.13+

• Node.js v12.18.4+

• GNU Make 3.81+ (optional, commands from the Makefile can be invoked by hand)

• Local or remote IPFS node

How to run

There is a demo script which makes an end-to-end execution of the entire flow. To run it, you need to go through several simple steps:

1. Install and run a local IPFS node (or use a remote one). In case you need to customize the IPFS url, you can do it by setting the storage.url property in the publisher and purchaser config files placed in the config directory.

2. Run the local Ethereum node by invoking:

   make run-ethereum

   After that, a local Ethereum node powered by Ganache will be up and running.

3. Deploy the smart contracts:

   make deploy-contracts

4. Run the demo script:

   make demo

   The whole publish and purchase flow will be executed.