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.
Users can employ unused hard disk capacity to mine Bitcoins without the need for expensive mining rigs and other specialized hardware. Traditional mining hardware is energy intensive, noisy, produces a lot of heat, and is becoming increasingly specialized, moving beyond the means of ordinary people. With BHD, mining is simple and accessible. POW-based mining is all about raw computing power and energy output, whereas BHD's POC-based mining is far more energy efficient and returns to Satoshi Nakamoto’s original ideal that mining would be decentralized and performed by ordinary people. POC (Proof of Capacity) scans are only performed once every few minutes. For the rest of the time the hard disk is on stand-by with negligible power usage, greatly reducing energy costs. Based on capacity proof, it will support super-large blocks in the future and will add functions such as zero-knowledge proof. Solid-state drives are expensive, POC has no requirement for fast data processing, only capacity, so POC naturally eliminates ASIC chips. Currently, the amount of energy expended globally in POW mining is greater than the total energy output of 159 countries. The development of digital currencies shouldn’t have to be built on the wasting of resources. With BHD, POW calculations can be completed with a minimum of computing and energy resources.