This is a decentralized data marketplace that allows data consumers to place bids on auctions for high-value sensor/IoT devices to compensate for invaluable data.

Data Marketplace is governed by specific contracts deployed on Ethereum network, allowing data curators to register new data sets and users to subscribe to existing data sets, in conjunction with IOTA network to preserve and validate data source.

Data Marketplace contract is publicly available and can be used by any other contract in the network. The smart contract stores each of the data sets metadata (owner, price, number of subscriptions, etc.) and information about each subscription to any data set (price, start time and end time).

Registration is the process through which data providers can offer their datasets on the Data Marketplace. Data providers are paid for their dataset after the subscription period ends for any given subscriber, through a withdraw transaction.

A Subscription holds the reference to instances of user-defined Contracts.

The subscribers are the users in the Data Marketplace that pay for data. Every payment is first made to the Marketplace contract and is held until the Subscription is expired or the Data curator is punished (should their data stop being available). In case the data provider was punished then and only then, the subscriber will able to ask for a refund. The refund is prorated on the fraction of the monthly subscription when the data was available, and will be deposited back to the subscriber's address.

Contracts are the custom and user defined artifact that describe a data subscription service. These are custom contracts that the buyer interacts with. The existence of these contracts live within subscriptions. Additional client code accompanies Contracts, where either the consumer and service provider run a custom client and server.

• Ganache
• solc compiler
• Truffle

npm install
npm install truffle -g
npm install ganache-cli -g

ganache-cli --account 4

truffle compile
truffle test