Qtum is a decentralized and open-source smart contracts platform and value transfer protocol. Qtum uses proof-of-stake consensus, meaning node operators are rewarded for validating transactions. It is a DGP governed blockchain where community participants can vote to change certain network parameters. Qtum is built on a bitcoin core fork, but the foundation has created its own hybrid blockchain with the help of several key tools. The coin uses bitcoin’s chain because of its simple and stable nature, allowing the foundation to build upon it more easily. As the QTUM project is a hybrid of Bitcoin and Ethereum, its team comprises of members from both Bitcoin and Ethereum community. They also have team members who formerly worked with Tencent, Alibaba, Nasdaq etc. Apart from that, they are backed by some notable VCs and prominent people from the Blockchain community such as Patrick Dai (Project Co-Founder), Neil Mahi (Chief Blockchain Architect/Co-Founder) and Jordan Earls (Lead Developer/Co-Founder). Qtum provides a Turing-complete blockchain stack and is able to execute smart contracts and decentralised applications like the Ethereum blockchain. Qtum builds on Bitcoin's UTXO transaction model and uses the Proof-of-Stake algorithm. It is backed by some highly prominent members of the blockchain community such as Anthony Di Iorio, Xu Star, Bo Shen, David Lee, Jehan Chu and Roger Ver. Qtum sold over 10 million dollars’ worth of its tokens after only 90 minutes, eventually raising a total value of $15.7 million before stopping the campaign early after only 5 days. They raised a total amount of 11,156.766 bitcoins (BTC) and 77,081.031 ether (ETH) in exchange for the 51 million Qtum tokens being distributed to the public. In Qtum’s whitepaper, 51% of the coins were distributed to the public via the crowdfunding campaign. Of the remaining 49%, 29% of the coins would be allocated as community incentives, and the remaining 20% would be distributed to the early backers and development team.
Tezos is a coin created by a former Morgan Stanley analyst, Arthur Breitman. It is a smart contract platform which is does not involve in mining Tezos coins. It is a coin that promotes themselves on major ideas of self-amendment and on-chain governance. It is an Ethereum-like blockchain that hosts smart contracts. It allows the community to vote and improve its flaws. Any token holder may delegate their voting rights to others in the network. The coin uses a generic network shell which allow different transaction and consensus protocols that a blockchain needs to be compatible. The source code is implemented on OCaml which is a fast, flexible and functional programming language which should suit an ambitious project and its technical requirements. Tezos’ proof-of-stake consensus algorithm is different from the delegated proof-of-stake (dPOS) where they go by the name liquid proof-of-stake. This liquid proof-of-stake that Tezos uses focus in filling the gap between both security and decentralization but still being able to take advantage of the benefits that delegated proof-of-stake offers. The staking process in Tezos is called “baking”. In this blockchain, bakers who make deposits will be rewarded for signing up and publishing blocks. However, if a baker commits any bad behavior the deposits will be forfeited. Baking & Endorsing Baking is what Tezos refers to as the action of signing and publishing a new block in the chain. Bakers need at least 10,000 XTZ to qualify as a delegate, and having additional delegated stake increases their chances of being selected as a Baker or Endorser. At the beginning of each cycle (4096 blocks), the Bakers for each block are randomly selected and published. Bakers earn a block reward of 16 XTZ for baking a block. In addition to the Baker, 32 Endorsers are randomly selected to verify the last block that was baked. Endorsers receive 2 XTZ for each block they endorse. Block Rewards & Inflation Block rewards are funded by protocol defined inflation. Rewards are calibrated so that the number of XTZ tokens grows at roughly 5.5% per year. If 100% of Tezos tokens are delegated, the annualized yield will be 5.5%. Currently, 38% of Tezos tokens have been delegated, including the 10% owned by the Tezos Foundation, so the annualized yield is currently 14%. To ensure Bakers and Endorsers act honestly, they are required to post a security deposit for each block they Bake or Endorse. They forfeit this deposit in the event of malicious activity, such as double baking or double endorsing a block. In 2018, Tezos successfully launched their main network after delaying the launch due to corporate governance disputes. The Tezos foundation planned to transition the network to a mainnet, or a more complete version. The foundation has also raised $232 million in July 2017 to build the network and issue a new type of cryptocurrency to its backers in one of the largest- ever initial coin offerings. The founders have also made it clear in their blog that the network is using a new blockchain technology hence unexpected issues may still occur affecting the network. Check out CoinBureau for the complete review of Tezos.