Qtum (QTUM) is a public blockchain-enabled platform that aims to “leverage the security and simplicity” of Bitcoin’s UTXO (unspent transaction output) protocol. In a manner that’s similar to how Ethereum, Tron, and EOS allow users to develop distributed ledger technology (DLT)-based applications, the Qtum platform also lets developers build software solutions on top of its blockchain network.
As detailed in an explainer video on Qtum’s official website, the DLT-powered platform decouples (or separates) applications from a blockchain’s underlying protocol by using an account “abstraction” layer.
Decoupling Applications from the Base Layer Improves Performance
According to Qtum’s developers, decoupling applications from the base layer “helps maintain the performance” of a blockchain network. Additional smart contract functionality may also be added to a DLT network after software programs have been separated from the underlying protocol.
In order to process transactions on its network, the Qtum blockchain uses a proof-of-stake (PoS)-based consensus algorithm. Qtum’s “decentralized governance” model allows its community members and stakeholders to cooperatively make decisions related to network management - such as changing the block sizes and gas fees (required for settling transactions).
Upgrading Blockchain Protocols Without “Ecosystem Disruption”
While proof-of-work (PoW)-powered blockchains also allow network participants to submit proposals for making improvements to the protocol, Qtum’s technical team believes their governance model allows developers to upgrade platforms without “ecosystem disruption.”
Contentious hard forks (backwards incompatible updates) such as the Bitcoin Cash (BCH) upgrade on November 15, 2018 caused the cryptocurrency’s blockchain to split into two separate networks. After the controversial fork, many crypto investors were confused about which chain should receive the BCH ticker.
In addition to users not knowing exactly how to redeem their coins after the network split, there had also been reports of critical security problems affecting the Bitcoin (“Satoshi Vision”) SV chain.
Due to a software bug in the Bitcoin SV codebase (as demonstrated in a video), users could have potentially engaged in double spending on the cryptocurrency’s network.
Due to these issues with PoW-based consensus algorithms, the creators of second and third-generation cryptocurrency platforms such as Qtum have been developing PoS-based blockchains.
Proof of Stake Chains Provide a More Efficient Way of Reaching Distributed Consensus
Digital asset platform developers who prefer PoS over other blockchain consensus protocols, including Qtum’s developers, argue that proof of stake chains may provide a greater level of security.
More than 5,000 Active Nodes Online
According to Qtum’s technical team, PoS-based protocols also provide a more efficient approach to establishing consensus on blockchains. Cryptocurrencies such as Bitcoin (BTC), which are based on proof of work consensus, consume a lot of electricity as they require mining (for validating transactions) - which may be harmful to the environment.
Currently, there are more than 5,000 active nodes online that are supporting the Qtum protocol. Notably, the Qtum blockchain has been functioning properly - without experiencing any down time for over a year.
In order to further improve the Qtum protocol, its developers have been working on various projects including “Unita” and Qtum’s x86 virtual machine (VM). Launched in April 2019, Unita is an automated data exchange and storage solution that can process over 10,000 transactions per second (TPS).
Qtum’s Unita Protocol Designed to Save Network Resources
As noted by Qtum’s development team, the Unita protocol is based on a scalable consensus mechanism, called SCAR. The SCAR algorithm has been designed to save data storage space and the network bandwidth required for building decentralized applications (dApps).
Notably, Qtum’s Unita protocol update could potentially allow the platform to process millions of transactions per day. The latest upgrade to the Qtum network also features more efficient data management, cross-chain trading capabilities, and the ability to store private information on Unita’s permissioned network. Users may also transfer data from the permissioned chain to a public platform supported by Unita.
Qtum’s Virtual Machine to Support Mainstream Programming Languages
Qtum’s VM supports the most widely-used programming languages for building enterprise-grade applications. These include C, C++, Python, and Rust.
Additionally, Qtum’s developer tools include a comprehensive set of software libraries, “parallel contract execution” functionality, and “native tool chains.” According to Qtum’s technical team, these features have been developed to improve gas efficiency on the platform’s blockchain
Proof of Stake Chains “Promise Significant Performance Advantages”
According to Qtum’s whitepaper, PoS-powered blockchain platforms “promise significant performance advantages” over PoW chains. Qtum’s technical team also notes that cryptocurrency platforms require “stable backwards-compatible smart-contract systems.”
Backwards compatible programs are needed to automate “cross-organizational information-logistics orchestration” with lite mobile wallets that provide simple payment verification (SPV) techniques. As explained in the Bitcoin whitepaper, SPV allows lightweight clients to validate transactions on a blockchain, without having to download the complete transaction history associated with a cryptocurrency platform.
SPV Techniques Used to Conduct More Efficient Transactions
Updating smart contract code can become difficult if a crypto network regularly experiences hard forks. To solve this problem and to also simply blockchain data management, Qtum’s technical team will employ SPV techniques to efficiently conduct transactions - as these don’t require checking the entire transaction log of a blockchain.
First Atomic Swap with Bitcoin Completed on Qtum Blockchain
In January 2019, Qtum’s developers successfully completed the first Bitcoin-based atomic swap on the Qtum blockchain. Atomic swaps allow users to conduct on-chain exchanges between cryptocurrencies that belong to two different and independent blockchain platforms. Third-parties are not needed to finalize transactions involving atomic swaps.
The ability to perform atomic swaps suggests that it may be possible to implement trustless interoperability between independent blockchains. According to Qtum’s development team, atomic swaps were performed using Hash Time-Locked Contracts (HTLC). These contracts lock user funds until an atomic swap transaction is confirmed by both blockchains involved in the transfer process.
Qtum Tokens May Be Used for “All Point-of-Sale Payments”
In March 2019, the Singapore-headquartered Qtum Foundation and UK-based fintech firm, Zuex announced that QTUM tokens would be listed in a crypto mobile payment wallet (developed by Zuex). As mentioned in the announcement, Zuex’s crypto wallet may be used for “all point-of-sale payments.”
On May 2, 2019, the Qtum Foundation introduced a complete set of developer tools for blockchain platforms. The new tools were released through a partnership with Google Cloud.
Qtum's technical team noted that the newly released software include “free-to-use” tools, which allow both tech-savvy and non-technical users to launch nodes and create applications on the cryptocurrency’s blockchain.