Qtum quantum chain is an open source smart contract platform combining the advantages of Bitcoin and Ethereum.

It aims to "adapt to social technology applications, adopt formal semantic language expressions, and provide a library of smart contract templates for rapid industry deployment of best practices".

1. Lack of new smart contract platforms. At present, the existing smart contract platform is mainly based on Proof of Work (POW), but the Proof of Work (POW) consensus mechanism is difficult to be deployed on a large scale by industrial applications. 2. Compatibility between different blockchain technologies, such as bitcoin ecosystem based on UTXO model and one development ecosystem based on Account model, is difficult to be compatible. 3. Consensus mechanism itself lacks flexibility, because different participants have different requirements for consensus mechanism in public chain and alliance chain. 4. Lack of consideration of industry compliance, for example, it is difficult to guarantee the existing blockchain system of Identity and KYC, which are required by the financial industry. 5. The existing blockchain system is very closed. At present, most of the trigger conditions of smart contracts come from the Courier system itself, and there are few trigger conditions from the outside world, which lack interaction in the real world

Quantum chains are designed to be compatible with bitcoin systems. Quantum linked virtual machines will remain EVM compatible. Because all the smart contracts developed on ethereum can also run on quantum platforms, so. Quantum chain. It also has Ethereum compatibility. The quantum chain itself has downward compatibility, so files and smart contracts created using the old version will continue to run on the new version without users. Mandatory upgrades, which will bring a lot of convenience to users. The quantum chain ease-of-use policy is aimed at the ease-of-use of nodes. The quantum chain will provide two or three different modes of operation for users' wallets. For respectively. Different user operating systems and development needs to provide a complete PAI service for Qtum systems, which will be based on Standard JSON-RPC. To provide remote local API call services.

As a store of value and a medium of payment; As a basis for mining; GAS charges as smart contract with DApp.

Qtum quantum Staking uses PoS consensus to ensure network security and consensus. In ITS prototype, Blackcoin's VERSION of PoS 3.0, network participants take Token Staking by holding tokens, validating network transactions and generating blocks. The probability of winning a new block is proportional to the network weight. If network participants are dishonest and try to game the system, PoS will penalize them by confiscating some or all of the tokens they are Staking. There are no barriers to entry for STAKING Qtum quantum chains, so the network is more decentralized. The challenge is that if the gain from cheating is greater than the penalty, the less QTUM staking a node holds, the more likely it is to cheat. The Qtum quantum chain uses Token's "maturity" mechanism to increase the cost of attack. Tokens must be "mature" (that is, 500 blocks confirmed) before they can participate in Staking. Qtum quantum chain also chooses PoS because PoW consensus mechanism is energy intensive, wasteful and not conducive to sustainable development. In the Qtum quantum chain, a maximum of 2MB blocks are generated every 144 seconds. Inflation is currently set at 1% a year and is scheduled to halve every four years for 32 years. At the time of writing, the circulation supply of QTUM is about 88.5 million, with an estimated maximum supply of ~ 107 million. The current block reward is 4 QTUM. 0.4 QTUM is a reward for creating blocks that are locked until they mature (500 blocks). After the initial 0.4 bonus matures, the remaining 3.6 QTUM is allocated over nine blocks. Qtum quantum chains use locking and delayed rewards to ensure security, making it difficult for others to attack the network.

1. Smart contract: Starting from the defect of limited large-scale application due to the lack of real application in the bitcoin ecosystem and Ethereum ecosystem, the quantum chain introduces the newly designed master contract and completes the execution of the contract through the common input of off-chain data and on-chain data as the trigger condition. 2. Compatibility: Starting from the incompatibility between the bitcoin ecosystem based on UTXO model and the Ethereum ecosystem based on Account model, quantum chain realizes compatibility with the Ethereum framework through the core infrastructure of Bitcoin. 3. Compatibility: Starting from the lack of consideration of industry compliance in the existing blockchain system, quantum chain attaches importance to industry compliance, increases consideration of industry qualifications, and provides optional identity identification modules.

QTUM will block rewards and transaction cost allocation by block producers exclusive changed to: rewards and transaction costs in the network multiple Shared each other between miners, namely producers in the block of time will receive 1/10 of the total cost, and after a predetermined block set the time, can receive another 9 1/10 the cost of a piece.

The Qtum Quantum chain team believes that Bitcoin is the most mature and stable blockchain at present, thus using Bitcoin Core as the Core foundation of the project. However, bitcoin cannot run the Turing-complete code required for smart contract writing, so the Qtum quantum chain combines ethereum Virtual machines (EVM) and, in the future, other virtual machines that can support dApps development. Bitcoin uses the UTXO model, while Ethereum Virtual Machines (EVM) and other virtual machines use the account model to ensure simplicity. To make bitcoin's UTXO model compatible with the virtual machine's account model, the Qtum quantum chain adds an "interaction layer" between the two, called the Account Abstraction Layer (AAL). Running Bitcoin Core enables an updated iteration of the Qtum quantum chain to integrate Bitcoin development, while integration with the Ethereum Virtual Machine (EVM) allows Ethereum developers to place dApps on the Qtum quantum chain platform. Qtum quantum Chain has officially announced that it is developing x86 virtual machines that will support smart contract authoring and dApps development in more major development languages in the future. Consensus: Qtum uses Blackcoin's version of PoS 3.0 to reach consensus, while Bitcoin and Ethereum currently use proof-of-work consensus (PoW).

The project has not yet achieved all the functionality outlined in the white paper. Project information disclosure is not perfect.

Quantum chain is a well-known public chain project in China. The team has done a good job in publicity and promotion, and has borrowed a lot from BTC and ETH in terms of technology. The underlying technology lacks originality, and there is a big gap between the project implementation and mainstream public chain projects. The disclosure information of team members' resumes is true and accurate but insufficient. Tokens are mainly used as stores of value and payment media, and their value is supported by the acquisition of transaction fees. The subsequent development of quantum chain depends on the implementation of its application.