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.
Quarkcoin is a coin which increases security by using 9 rounds of hashing from 6 different hashing algorithms - blake, bmw, grøstl, JH, keccak, skein. 3 of the hashing rounds apply a random hashing function. This compares with Bitcoin's solitary use of SHA-256 algorithm. There is no pre-mine for this coin. A new block is generated every 30 seconds and 2048 Quark is given out as reward per block at the beginning. This reward halves every 60480 blocks or roughly every 3 weeks. The initial supply of Quark is 247 million and this is expected to be mined in roughly 6 months since launch date. The supply will then continue to increase at an inflationary rate of 0.5% per year. Quarkcoin was launched on 21 July 2013.