Frequently Asked Questions

What is a smart contract oracle?

Whenever a smart contract contains a contingency, like payment conditional on an event, the contract needs to be informed in a reliable manner. This is what the smart contract oracle does. Oracles are also needed to inform smart contracts about financial data, such as exchange rates, security prices, and interest rates. One of the main applications of oracles is currently the reliable creation of random numbers for gambling purposes, but Blockchain Presence aims at offering a much broader scope of informational input.

Why do you need Blockchain Presence as a smart contract oracle?

Existing smart contract oracles are not secure because they rely on off-chain authentication. Blockchain Presence offers a three-step on-chain authentication method, and is thereby as secure as the underlying smart contract environment (Ethereum). Another reason for using Blockchain Presence is that it aims at being the most cost-efficient solution to the problem of procuring informational input for smart contract applications. This cost efficiency is achieved primarily by avoiding the inefficient request on providers of information to hold expensive and risky collateral tokens.

How much does it cost to order data from the Blockchain Presence platform?

Once you know which data you wish to order from Blockchain Presence, you include an order function call and a mailbox function into your smart contract. The order function call specifies which data you are ordering, and when you wish to have it delivered to your smart contract. The mailbox function in your smart contract will be called once the data has been sent by your sender of choice. Coding examples for the order & delivery process are provided on Github.

Why would senders want to provide data to Blockchain Presence?

There are three main motivations for becoming a sender. One is that being a sender is an inexpensive way to get into contact with the blockchain world. Another reason is that a sender might wish to ensure that data he feels responsible for is available for smart contracts. Finally, a sender may choose to charge fees on the information provided for smart contract applications.

Is it difficult to become a sender?

No. First you register, which is needed for the three-step on-chain authentication. Then, you install the Sender Convenience Applet on your pc or server. Finally, you upload a description of the data that you commit to provide.