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.
Horizen is an inclusive ecosystem where everyone is empowered and rewarded for their contributions. Horizen’s massively scalable platform enables businesses and developers to quickly and affordably create their own public or private blockchains utilizing the largest node network in the industry. Horizen’s Sidechain SDK provides all necessary components for easy and fast deployment of a fully customizable blockchain. Horizen's native cryptocurrency, ZEN, is a mineable PoW coin currently trading on exchanges including Bittrex, Binance, and Changelly. ZEN is integrated on major wallets including Horizen's flagship app, Sphere by Horizen, a multifunctional wallet that serves as an interface with most Horizen products and services.