- Qtum is a blockchain network that combines Ethereum’s smart contract with Bitcoin’s UTXO transaction model.
- Qtum uses MPoS, a custom variant of PoS, for its network security.
- x86VM is a Qtum product where smart contracts can be written in popular coding languages like C, C++, Go, Rust, Java, and Python.
Qtum, Another Among the Dozens
The rising competition in the blockchain network has led to inventions and technologies constantly coming up claiming to solve the rising challenges.Qtum is another blockchain network founded in 2016, but launched in 2017. Qtum envisions combining the different features of bitcoin and ethereum to create a more flexible space for developers to work.
If we go to the specifics, then Qtum uses Bitcoin’s UTXO (unspent transaction output) with a model similar to EVM (Ethereum Virtual Machine), which allows users to develop applications on a blockchain and participate in transactions like Bitcoin.
Unique Features of Qtum/ How It Works
Bitcoin was powered by the Proof of Work (PoW) model, where miners solved a puzzle (called mining) and were rewarded for the correct solution. This, however, consumed a huge amount of energy because of the competition among miners who used heavy machinery, and an energy-efficient PoS (proof of stake) was launched.
Ethereum was powered on PoS, where the validators at first kept some amount of crypto at stake, and then in proportion to their stake, the chances of them being selected to solve the puzzle increased. This method proved carbon-efficient and was employed in later developed blockchains.
Qtum, taking a step further, uses MPoS, an advancement in PoS, which protects users from junk contract attacks. Also, validators who stake their coins for a long period are awarded more than those who keep their wallet offline, thus preventing double-spend attacks.
Decentralised Governance Protocol (DGP):
Decentralisation has always been the core idea around blockchains,and Qtum works well in this regard. It follows DGProtocol, which keeps the blockchain running even if some nodes become non-functional. Block size, gas price, and other similar parameters can then be easily modified.
Account Abstraction Layer (AAL):
It will not be wrong to call AAL the magic sauce or secret ingredient of AAL. As we already understand, Qtum stands on the UTXO bitcoin model, but the developers can still create and execute smart contracts, as they did in Ethereum. AAL had made this possible by altering a few codes in Bitcoin.An understanding of the two different layers discussed here will make AAL more clear.
Layer 1: The UTXO
UTXO, or “Unspent Transaction Output” is the currency that remains after a crypto transaction has been completed. UTXO is the underlying element of Bitcoin and many other cryptocurrencies, which guides us when a transaction starts and ends.
Harry has a guitar worth 0.3 BTC, and Linda is interested in buying it. Now, UTOX differs from the bank account system we are familiar with, where our account, a virtual space, holds some money and Linda, on entering 0.3 BTC, will pay to Harry.
UTOX works on a model of input and output, where the output of one becomes the input of another.Linda will first verify all her inputs, Let’s suppose she has these three.
Chad to Linda = 1 BTC
Mark to Linda = 0.7 BTC
Abraham to Linda = 0.2 BTC
Now, Linda can choose among her inputs to pay Harry. Let’s assume she chose the one from Chad, and after the transaction, 0.7 BTC remains. A part of this 0.7 will be used by miners as mining fees, and the rest will be returned to Linda’s account. Hence, Linda, on spending her input (i.e., 1 BTC) created two outputs ( i.e, 0.3 and 0.7). This model helps in keeping track of the bitcoins at any point in time.
Layer 2: The Virtual Machine Layer
EVM, or Ethereum Virtual Machine, serves its purpose of executing smart contracts and the dAPPs made over them. It powers all the applications that are running on the Ethereum network. However, in the EVM, all the smart contracts can be written only in a specific code language called Solidly, which limits its users and developers.
The x86 Virtual Machine:
Qtum developed its own virtual machine and named it x86VM, a platform for the creation and execution of smart contracts on the Qunta blockchain.X86VM supports a number of basic and popular programming languages like C, C++, Java, Rust and Python making dAPP development flexible. The gas cost per transaction is significantly reduced in x86 because of its use of a unified 16-bit coding scheme to register operations, allowing increased TPS.
