Smart contracts on Ethereum are fully self contained and any information or access to off-chain data is restricted. Tellor solves this problem by creating a system where parties can request the value of an off-chain data point (e.g. ETH/USD) and miners compete to add this value to an on-chain data bank, accessible by all Ethereum smart contracts. Inputs to a data series are secured by a network of staked miners. The main Tellor smart contract creates a time series of each requested data series and aims to become the standard source of high value data for decentralized applications. This oracle, “Tellor”, utilizes similar incentive mechanisms to other cryptocurrency systems through the issuance of Tellor’s token, Tributes, that are used to request a particular data series from miners.
FNKOS is a fog computing-based blockchain operating system designed to make the best use of the edge computing resources such as idle hardware network and storage resources. The fog blockchain was built on the basis of a PoC (Proof of Contribution) consensus algorithm: nodes get FNKOS incentives according to their contribution in the fog blockchain based on network flow, storage volume, computational capacity.