International Financial Times: "Quantum Chain builds a bridge with existing blockchain platforms such as Bitcoin and Ethereum"

Many well-known blockchain investors, including OKCoin CEO Mingxing Xu, Ethereum early participant Anthony Di Iorio, Augur co-founder Jeremy Gardner and Distributed Fund partner Shen Bo, have provided financial support for the Qtum project.

Qtum is a smart contract platform based on the UTXO model. It combines the advantages of Bitcoin's unspent transaction output model (UTXO) and Ethereum Virtual Machine (EVM), and has a flexible consensus mechanism for public chains to achieve compatibility with Bitcoin and Ethereum. In addition, Qtum has also introduced the design of Oracle and data feeds, making Qtum a bridge between the blockchain world and the real business world. At the same time, Qtum can also be compatible with other UTXO-based blockchain platforms, such as Hyperledger and R3 Corda platforms.

It is not easy to make the two ecosystems of Bitcoin and Ethereum compatible. In the Bitcoin UTXO design, the unspent output of the previous transaction can be used for the current transaction and supports concurrent processing. Ethereum uses the Account Model. The stateless property of UTXO is not suitable for relatively complex application development, such as asset insurance and transfer; and the UTXO model cannot meet the functions of multi-party participation and data feed of smart contracts.

Shuai Chu, who holds a Ph.D. from the Chinese Academy of Sciences and is the co-founder of Qtum, mentioned that Qtum innovatively designed the "Account Abstraction Layer" (AAL), where developers only need to add contract status and account information to the Qtum Account Abstraction Layer.

Shuai Chu also added,

“The account abstraction layer works like a converter that creates contract state and account information for each UTXO, making it easier for the EVM to process UTXO-based contracts. All UTXO-based blockchain platforms, such as Bitcoin, Litecoin, and even Hyperledger and R3 Corda, use the newly designed account abstraction layer to implement smart contracts.”

Shuai Chu mentioned that at last year’s Shanghai Blockchain Summit, he had in-depth discussions with many members of the Hyperledger project. “Hyperledger developers also have great interest in Qtum, and AAL can also enable EVM to run Hyperledger’s smart contracts. The launch of AAL enables all blockchain platforms based on the UTXO model to use EVM to run smart contracts without obstacles.”

Regarding the complexity of multi-party participation in smart contracts, Shuai Chu said, "AAL can meet the multiple parallel inputs of the UTXO model, but due to the limitations of EVM, it currently only supports a single output."

"In the subsequent development and design process, we will expand the functionality of EVM to support multiple inputs/outputs of a single contract. In Qtum, we define two types of transactions, standard transaction types and contract transaction types. Standard transactions are similar to Bitcoin transactions and can transfer funds from one address to another. Contract transactions need to be executed using the newly defined operation code (opcode) in the quantum chain."

Qtum has added an incentive mechanism based on the Proof of Stake (PoS) consensus mechanism proposed by Sunny King. "In view of the many potential attacks faced by the classic PoS consensus mechanism, the Qtum team has fixed a large number of security vulnerabilities in PoS and added incentives to estimate the nodes online, incentivizing nodes in the network to stay online to maintain the stability and security of the network."

“We will release the latest technical white paper before Ethereum Casper and provide a detailed introduction to PoS 3.0.”

“As for the choice of Qtum source code, we have previously considered using a completely new code, but it would take a lot of time to develop and test. Therefore, we wrote the Qtum source code based on the Bitcoin source code.”

“After the release of the Qtum main chain, we will try to develop side chains. This can greatly reduce the waste of main chain computing resources and significantly improve the operating efficiency of the Qtum platform,” Shuai Chu added.

It is reported that the Qtum project has also established close cooperation with one of the world's four largest accounting firms (specific information has not yet been disclosed) and received more than one million US dollars in investment in the angel round. Investors include Chen Weixing, co-founder of Kuaidi; Anthony Di Iorio, an early participant in Ethereum and CEO of JaxxWallet; Jeremy Gardner, co-founder of Augur and resident entrepreneur of Blockchain Capital; Li Guoquan, founder of LeftCoast, Libai, and DLEE Capital Management; Shen Bo, general partner of Distributed Fund; Jehan Chu, managing partner of Jen Advisors, Gao Qingzhong, strategic cooperation director of Huawei Technologies Co., Ltd.; Xu Mingxing, CEO of OKCoin; Yi Lihua, partner of Zhongwo Investment; and Li Xiaolai, one of the world's largest Bitcoin holders and angel investor in blockchain projects.