Qtum Chain Completes the First Smart Contract Platform for Bitcoin UTXO Model

Recently, the Qtum Foundation released a development summary and progress, and completed the first POS smart contract platform based on the Bitcoin UTXO model. It has also become the second blockchain platform after Ethereum that fully supports Turing-complete smart contracts.

Qtum Chain is based on the classic Proof of Stake mechanism as its consensus mechanism, which is different from the Proof of Work mechanism of Bitcoin and Ethereum. It is the first smart contract platform under the POS mechanism in the entire blockchain industry, and it is also the first smart contract platform to support the Bitcoin ecosystem through EVM.

Let's take a look at the development details and progress:

Completed development milestones:

1- The Qtum Chain model design has been completed

In the process of designing the Qtum chain, the first challenge we faced was to create a Qtum chain model that is compatible with the Ethereum virtual machine and the Bitcoin UTX transmission model. Considering that the native Ethereum virtual machine uses a state database, we must expand the functionality of the Ethereum virtual machine to support the UTXO transaction model.
In the Qtum model, we use the state database to store smart contract code and related data, and use the UTXO transaction model on the Qtum virtual machine to perform all fund-related operations.
After completing the design of the Quantum Chain model, we started the actual development of the Quantum Chain.

2- Qtum: The first smart contract based on the UTXO model has been completed and passed the test.

The development of Qtum is based on the Bitcoin Core code (version 0.13) and the Ethereum Virtual Machine cpp-ethereum. We integrated the Ethereum Virtual Machine code and dependencies with the Bitcoin Core code, and added the creation of Qtum smart contracts, contract funding, and the call of Bitcoin scripts to the Qtum model. In addition, we also added the UTXO transaction model to the Qtum virtual machine.

Other development work has also been completed, such as the Quantum Chain Gas model, Quantum Chain virtual machine, Coin Picking algorithm, etc.
Now, we have completed the development of the quantum chain model and are conducting comprehensive testing.

3-The core proof-of-stake consensus mechanism has been completed and is in the code review stage.

We have now deployed a number of POS nodes, ported the Proof of Stake consensus mechanism (PoS 3.0) algorithm to Bitcoin Core version V0.13, and completed the final testing. This part of the code is currently in the review stage.

What are the subsequent development plans?

1- Qtum Wallet

We have started to develop a new PC desktop and mobile version of the Qtum wallet application. For the desktop wallet, in addition to providing traditional wallet functions, we are developing a more flexible and user-friendly wallet application. The Qtum wallet will also support the execution of smart contracts and some new innovative features.
For the mobile version of the Qtum wallet, we have developed versions based on iOS and Android, which have now entered the testing phase.

2- Integration with Proof of Stake Consensus Mechanism

Regarding the consensus mechanism of the quantum chain, we are currently integrating Qtum's virtual machine and the equity consensus mechanism. After this stage is completed, Qtum's first test network will be released.

3- Testing before the launch of Qtum

We have now entered the comprehensive testing phase of the Quantum Chain. In addition to automated and manual testing of Bitcoin and Ethereum virtual machines, we have also developed a test script tool specifically for the Quantum Chain. After completing internal testing, we will invite well-known software developers and institutions to review and test the source code.

4- Release the first test version of Qtum: Sparknet test network (testnet)

Once the Qtum prototype has been tested internally and externally, we will release a test version called Sparknet, which will be the final version before the official release.

Finally, the Quantum Chain Foundation wishes everyone a happy new year!