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.
Ocean Protocol is an ecosystem for sharing data and associated services. It provides a tokenized service layer that exposes data, storage, compute and algorithms for consumption with a set of deterministic proofs on availability and integrity that serve as verifiable service agreements. There is staking on services to signal quality, reputation and ward against Sybil Attacks. Ocean helps to unlock data, particularly for AI. It is designed for scale and uses blockchain technology that allows data to be shared and sold in a safe, secure and transparent manner. The Ocean Protocol is an ecosystem composed of data assets and services, where assets are represented by data and algorithms, and services are represented by integration, processing and persistence mechanisms. Ocean Protocol facilitates discovery by storing and promoting metadata, linking assets and services, and provides a licensing framework that has toolsets for pricing. A multitude of data marketplaces can hook into Ocean Protocol to provide “last mile” services to connect data providers and consumers. Ocean Protocol is designed so that data owners cannot be locked-in to any single marketplace. The data owner controls each dataset.