QuarkChain Review — A New Scalable Blockchain Looking to Dethrone Ethereum?

QuarkChain is one of the new blockchains “on the block” that aims to create a highly scalable and secure blockchain that can handle up to one million transactions per second using a two-layered blockchain system.

They are seeking to bring crypto to wider mainstream audience and will support smart contracts with Ethereum Virtual Machine (EVM). This means developers will be able to easily port and deploy dApps built on Ethereum onto QuarkChain once their mainnet is live which could make QuarkChain a serious contender right out the gate.

We could see the likes of CryptoKitties and other dApps that require scalability shift their dApps over to QuarkChain if Ethereum is unable to solve their scalability issues in a timely manner.

Blockchain scalability is at the forefront of many people’s minds in the crypto community. It is one of the most hotly debated topics and trends going around.

But what is blockchain scalability?

Blockchain Scalability is:

the potential of a blockchain network to handle greater amounts of transactions

without incurring negative side-effects.

Let’s consider a football stadium with a capacity to hold 50,000 people for a second. The stadium can be said to scale well up to 50,000 people, however exceeding the stadiums capacity with say 75,000 people would have a grave impact on the safety and the experience of the patrons.

There would be longer queues than normal for food, drinks and toilets creating a poor experience for attendees. There would be standing room only and everyone would be bumping shoulders as they attempt to move around the stadium.

Blockchain Scalability Comes Down to Transactions

A transaction for a blockchain can simply be thought of as one user sending cryptocurrencies to another user.

• Bitcoin can support roughly 6 to 7 of these transactions per second
• Ethereum maxes out at around 15 transactions per second

This means Bitcoin and Ethereum’s scaling has a very low transaction throughput and as illustrated in the stadium example above; would lead to a negative experience for the attendees/patrons.

Transactions would crawl to a halt and take minutes instead of seconds to go through, transaction fees would skyrocket, and it simply would not be a enjoyable time for anyone involved.

The question then is how can blockchains achieve a higher level of transaction throughput so they are able to perform at higher transactions per second?

Blockchains vs Financial Payment Systems

Let’s compare Bitcoin and Ethereum to widely adopted transaction systems to date, Visa can handle 45,000 to 60,000 transactions per second during peak Christmas periods whereas AliPay is capable of a gigantic 200,000 transactions a second.

Chart comparison of QuarkChain’s transactions per second

For crypto to have any chance whatsoever of unleashing its full potential in disrupting many of the world’s incumbent industries, it is evident there must first be a solution to the limitations of blockchain scalability.

QuarkChain

QuarkChain aims to build a user-friendly, decentralized and reliable blockchain that can ultimately handle millions of transactions per second.

Scalability has been integrated into the design of QuarkChain from the get-go and with this in mind they’ve set out to build a platform capable of supporting industries ranging from FinTech to gaming and social media.

The Problem

There’s a saying in life that goes like this…

When you’re young you have time and energy, but no money.

When you’re an adult, you have money and energy, but no time.

When you’re retired, you have time and money, but no energy.

What a dilemma! Or should we say… trilemma?

Hmm, well is it really not possible to achieve all three? Of course it is!

A similar trilemma presents itself in blockchain however there has been no viable solution uncovered to date and this is exactly what QuarkChain along with many others in this space are attempting to solve.

The blockchain trilemma looks like this:

A permissioned (centralized) blockchain can provide scalability and security however loses all trace of decentralization. Permissioned blockchains are similar to centralized systems in the old world such as banks, Visa, as well as PayPal.

Opting for a permissionless (decentralized) blockchain such as Bitcoin or Ethereum provides security and a dispersed network however scalability is sacrificed, this was evident with the CryptoKitties dApp and excessive transaction fees when the demand on the Bitcoin network was high.

The real challenge therefore is figuring out how a blockchain can ACHIEVE ALL THREE:

1. Decentralization
2. Scalability
3. Security

Whomever is able to solve this trilemma will likely score themselves “a one-way ticket to the moon”!

But before we leap towards thinking about getting onto the moon, let’s take a step back and consider exactly why it is that decentralization, security, and scalability are essential components for a blockchain…

BLOCKCHAIN SECURITY

The two primary components that ensure the security of a blockchain are:

1. Making sure only valid transactions are made; and
2. That the network is safe and resistant to malicious attacks and users.

Ensuring that only valid transactions are made allows users of cryptocurrency to maintain a strong level of trust and confidence in the value of the crypto.

If a user can easily send tokens they don’t own and make new ones out of thin air, this greatly undermines the value of the cryptocurrency.

This would be similar to printing money out of thin air, which has been a regular practice for many reserve banks around the world for several years. The more money is introduced into any economy this will drive inflation up causing the currency being printed to drop in value..

When this is taken to extremes hyperinflation can occur as was the case in Zimbabwe and this can cause all sorts of mayhem, strife, and havoc.

DECENTRALIZATION

As the term implies decentralization is the opposite of centralization and in the case of crypto an extreme level of centralization would be having a sole miner for a blockchain.

Anyone transacting on this blockchain would need to have a great deal of faith and trust that this sole miner won’t do anything dodgy as make up fake transactions.

Even if people trusted this miner, the network would still be at great risk as now anyone interested in taking down the blockchain has a single target to attack. They can launch a denial of service attack on the miner taking the whole network down or look to bribe, blackmail, or manipulate the miner into doing their bidding.

SCALABILITY

As written above, decentralization and security are essential for the ecosystem, they provide a reliable and costly efficient space to continue evolving into future tech. On the other hand, as shown on the next diagram, as security and decentralization grows, an enormous amount of data , requirements for storage and bandwidth needs grow with it, which intrinsically implies a diminution in the system´s scalability.

Solution

As illustrated in the diagram below, there are three propositions to solving the problem of scalability:

• Multi-blockchains → They may suffer from vulnerability issues, double-spending attacks, reverse transactions or strategic mining attacks.
• Lightning network→ BTC´s option to this problem seems to be inefficient. User’s transaction targets are random and happen sporadically.
• Sharding→ Omniledger´s solution to the problem, with the intricate consensus protocol. It may be limited by cross-shards transactions and single shard take overs.

But partial solutions do not provide full efficiency especially in a time of exponential evolution. QuarkChain aims to fulfill the ultimate goal of any blockchain: Extending scalability far beyond current tech limits, while maintaining the balance for both security and decentralization.

QuarkChain’s bottom up approach to scalability begins by considering the two primary functions a blockchain serves as a public ledger which is:

1. Tracking the “state” of a ledger and all of the transactions that are made; and
2. Ensuring only valid transactions are confirmed and recorded onto the ledger.

1. The “State” of a Ledger

If you’re not sure what a ledger is, you can think of it as the thing responsible for keeping track of and recording everything that occurs in your bank account.

Your account has a running list of debits (when money goes out of your account — boo!) and credits (when money goes into your account — woo!) which are recorded whenever money is sent or received into your account.

The _“_state” of the ledger then is simply a snapshot of what’s in your bank account at any point in time, which is otherwise known as your bank balance! When a friend sends $50 into your account that has $100 in it, the new “state” of your account will then be $150.

An ancient Papyrus ledger

2. Confirmation of Transactions

If a transaction is made it doesn’t necessarily mean the transaction will go through and this is what confirming a transaction is all about.

Sending $100 to a friend with $50 in your account will see your transaction getting rejected! The transaction won’t be processed and confirmed as it is an invalid transaction due to insufficient funds in your account.

QuarkChain’s 2 Layered Blockchain System

QuarkChain separates out these two primary functions with the use of a 2 layered system that allows for greater scalability:

1. The first layer consists of “elastic sharded” blockchains; and
2. The second layer has a root blockchain.

The first layer with “elastic sharded” blockchains can be broken down as follows:

• Elastic: the sharded (minor) blockchains on this layer are elastic because the amount can be increased or decreased as required.
• Sharded — each sharded minor-blockchain only processes a small subset of all the transactions that occur so they are considered “sharded” as they represent a small fragment of all the transactions occurring throughout the network. (This is what enables QuarkChain’s scalability.)
• Blockchains — the minor-blockchains keep track of the current state of the ledger by processing and recording relevant data such as user accounts and the transactions made between accounts

The Second Layer and the Root Blockchain

The second layer serves the function of confirming the transactions that take place throughout the network. This is done by sending the block headers of the minor blockchains that contain all the transactions to the root blockchain, the root blockchain then confirms these transactions by creating a new block with all of the block headers.

QuarkChain’s 2nd layer system offers a higher amount of transactions per second whilst accounting for bottlenecks that occur from increased throughput such as computing power, data storage, and internet bandwidth.

Structure of QuarkChain’s 2nd Layered Blockchain

Are We Decentralized Yet?

QuarkChain incorporates several features to ensure decentralization of the network:

1. Collaborative mining driven by game-theoretic incentives to ensure when miners mine for their own selfish benefit that this behavior aligns with what is best for the overall system.
2. Mining difficulty algorithms are designed so that hash power is evenly distributed among sharded minor-blockchains and the root blockchain.
3. Each blockchain offers different rewards and difficulty levels so that weak miners can achieve similar levels of expected returns by mining solo when compared to joining a mining pool. This lessens the need for mining pools and results in less centralization.

Main Features — Tech Overview

Smart Contracts

QuarkChain supports smart contracts with the use of Ethereum Virtual Machine (EVM), sharded blockchains therefore run their own smart contracts local to their blockchain via EVM.

Sharded blockchains can be thought of as mini-Ethereum’s or clones of Ethereum running simultaneously and parallel to one another with unique individual wallets associated to them.

So for sharded blockchain 1, you will also have wallet 1, and on sharded blockchain 2 there is wallet 2, and so forth… As you can imagine it would be a hassle to keep track of these wallets, especially if there are a hundred or even thousands of these sharded blockchains, which is why QuarkChain offers the following two features:

1. Simple Account Management
2. Smart Wallet

In QuarkChain users are able to use a single “Primary Account” where the majority of the user’s funds will be parked for them to manage all other wallets. When a user wants to send funds to a different sharded blockchain the user simply sends it from their Primary Account.

Primary account sending transactions to wallets located in other sharded blockchains

The Primary Account is combined with a “Smart Wallet” to automatically handle “cross”-shard transactions, these “cross”-shared transactions can be made anytime and are confirmed within minutes.

(A cross-shard transaction is a transaction that is made from one sharded blockchain to another sharded blockchain, e.g. sending funds from Wallet 1 to Wallet 2 would constitute a cross-shard transaction, whereas a transaction made from one wallet to another wallet within the same shard, e.g. Shard 1, is considered an “in-shard” transaction.)

A cross-shard transaction in action: Shard 1 makes a transaction to Shard n.

Collaborative Mining

QuarkChain is a hybrid Proof-of-Work (PoW) blockchain that uses an ASIC-resistant PoW. The rootchain reaches consensus via PoW with each sharded blockchain following a “rootchain first” consensus to deal with forks.

Due to the two-layered system an advisor would need to first revert transactions (or block headers) on the root+chain in the second layer before they can attempt to revert transactions made on the sharded blockchain level.

In an early prototype, QuarkChain sharded blockchains were able to confirm blocks in 10 seconds and the rootchain confirmed blocks within 2.5 minutes.

Hash Power

As each blockchain in the network offers a different level of mining reward and difficulty, this allows miners to choose which blockchain to mine to achieve the best level of returns given their hash power.

This creates an open market for mining where the blockchains act as sellers touting block rewards, with miners buying block rewards with hashing+ power as their currency.

QuarkChain’s mining difficulty algorithms are designed so there is at least 50% of total hash power allocated to the root blockchain at all times with the remaining 50% being evenly distributed among sharded blockchains.

50% of total hash power from miners is allocated to the root blockchain with the remaining 50% evenly distributed between the sharded blockchains

A malicious user looking to attack QuarkChain requires at least 25% of the network’s total hash power, which is less than the 51% required for Bitcoin.

Clustering

Recording and keeping track of ALL transactions for a blockchain is resource intensive; doing this for a high-throughput blockchain is even more so.

Unfortunately this is how most blockchains such as Bitcoin and Ethereum function with miners who take on the role of “full nodes”.

For a high-throughput blockchain performing 500,000 transactions per second, these transactions would add up to requiring 10 terabytes of data to be stored each day by miners and an internet bandwidth of at least 1GB per second.

Miners capable of such demanding requirements would likely only be commercially ran mining operations and so the high amount of throughput would lead to the centralization of miners with the smaller miners taking their hashing power elsewhere.

This is why QuarkChain incorporates the concept of “clustering” miners so that mini-nodes are able to work together in order to create a full node.

Full-nodes (represented by blocks on the left) are replaced by a cluster of mini-nodes

Each mini-node within a cluster works to validate a subset of blockchains and then bands together to share what they’ve validated to form the complete picture of all transactions that have occurred throughout the network.

Jumping back to our banking account analogy, a full node can be considered as having the complete picture of all bank accounts held by a bank including all the transactions that have been made for each account.

A mini-node however only has a snapshot of the first hundred bank accounts and their related transactions, with a second mini-node covering the next hundred and so forth.

In order for mini-nodes to understand what’s happening in ALL bank accounts, they have to come together and share what they know to form the complete picture and make up a full node.

You can imagine just how difficult it would be for one accountant to keep track of all the different bank accounts and the transactions happening throughout. Splitting up the accounts and spreading them out over several accountants however makes the task a lot more manageable.

In the case of miners, this means the total amount of data that a miner has to store is far less than what they would be required to store if they had to operate as a full node.

Left: A cluster of mini-nodes A, B, and C each validate transactions from a subset of R: rootchain, S0: Shard 0 blockchain, and S1: Shard 1 blockchain.

Right: The mini-nodes work together in a cluster to create a full-node. Even if one of the mini-nodes is offline the cluster can still form the complete picture of R, S0, and S1.

Testnet

QuarkChain currently has a private testnet live that is operating with 8 sharded blockchains with each shard performing 100 to 200 transactions per second (TPS). The total TPS for the network currently ranges from 1000 to 2000+ transactions per second.

QuarkChain’s Testnet (Source: CryptoBriefing)

Roadmap

• Q1 2018 — White paper and developing verification code 0.1 proof of concept
• Q2 2018 — Release verification code 0.2 and implement Testnet 0.1 with Wallet 0.1.
• Testnet 0.1 supports basic transactions including both in-shard and cross-shard transactions
• Q3 2018 — Release Testnet 0.2 and Wallet 0.2.
• Testnet 0.2 supports further features such as smart contracts, reshard, etc.
• Q4 2018 — Release of QuarkChain Core 1.0, Mainnet 1.0, together with Smart Wallet 1.0
• Core 1.0 will provide basic functionality and basic optimization (e.g. GPU support) for QuarkChain.
• Q2 2019 — Release of QuarkChain Core 2.0, Mainnet 2.0, together with Smart Wallet 2.0
• Code 2.0 further optimizez Core 1.0 and enables clustering feature for mini-nodes to form a cluster and run as a full node.

Token Economics

• Token Name : QKC
• Hard Cap : 20 Million USD
• The QuarkChain token (QKC) will be an ERC-20 token until Mainnet 1.0 launches Q4 2018, the QKC (ERC-20) will then be converted to QuarkChain’s mainnet tokens.
• Crowdsale intended for end of May or start of June
• 2 year vesting period for the team with an extended vesting period for QuarkChain’s Foundation
• QKC will be used to pay for transaction fees and to reward community contributors that help improve QuarkChain’s system
• A significant amount of QKC will be dedicated to incentivizing developers to build dApps on QuarkChain’s platform

Potential Considerations

• QuarkChain supports EVM smart contracts and this should not be understated. If QuarkChain can provide a secure scalable blockchain before Ethereum solves their scalability issues we may see dApps that require scalability to migrate to QuarkChain resulting in greater amounts of users and developers.
• There are many competitors proposing a solution to blockchain scalability including the likes of Rchain, Zilliqa, Kadena, Thunder Token, Algorand, Ethereum, Bitcoin and more. It is unlikely one blockchain will rule them all, however it is also just as unlikely that all of these projects achieve widespread adoption.

• The open transparency of transactions could stifle potential partnerships as commercial entities may not want transactions to be publicly available.
• 25% of total hashing power is required to launch an attack on QuarkChain’s network. This percentage is far less than other blockchains and is a serious cause for concern, as a successful attack would greatly corrode the value and confidence in the network.
• To date no enterprise partnerships have been announced.

Team + Advisors

Development Team

Qi Zhou — Founder

• Qi Zhou achieved 10M tps as a member of the real time infrastructure team at Facebook
• Expert in scalability and was a key developer in achieving 10m IOPS with clustering for EMC
• 5+ years as a software engineer. Short stints with key roles at Facebook (1 year), Dell EMC (2.5 years), Google (9 months) and Ratrix Technologies (10 months).
• PHD from Georgia institute of Technology

Zhaoguang Wang — Software Engineer

• Zhaouang has 6+ years experience as a system backend engineer working on large complex distributed systems
• Key roles at Facebook (1 year), Instagram (4 months), Google (5 years)
• PHD and Masters degree in Computer Science and Engineering, University of Michigan

Xiaoli Ma — Research Scientist

• Professor at Georgia Institute of Technology (Combined 7 years, 10 months)
• Previously CTO and Co Founder of Ratrix Technologies (6 years, 5 months)

Yaodong Yang — Research Scientist

• Vice Chairman in Education at Xi’an Jiaotong University, Frontier Institute of Science and Technology
• Co-founder of Demo++ (Tech Incubator)
• Yaodong has authorized 50+ papers in peer reviewed journals and has over 600 citations in his name.

Wencen Wu — Research Scientist

• Wencen has been a Assistant Professor at Rensselaer Polytechnic Institute (4 years and 6 months).
• Has a MSC and PHD in Electrical and Computer Engineering

Operations Team

Anturine Xiang — Marketing and Community

• Anturine has 6+ years experience within finance and technology at Wall Street and Silicon Valley
• Key Roles as Lead Platform Analytics at Wish, Business Development and Marketing at Beepi, Consumer Marketing and Analytics at LinkedIn

Partners and Investors

Arun G. Phadke

• Arun is a University Distinguished Professor emeritus in the Department of Electrical Engineering at Virginia Tech
• Fellow of National Academy of Engineering, USA

Bill Moore

• Managing Director of Walden International (Global venture capital firm)
• Previously Chief Engineer Sun Microsystems who co-led the ZFS team, also Former President of DSSD/EMC (Dell)

Mike Miller

• Mike is a PhD Physicist with 100+ publications
• Founder of Cloundant which was acquired by IBM in 2014

Kevin Hsu

• Kevin is a serial investor in blockchain companies

Leo Wang

• Leo is a recognised cryptocurrency fund manager who invested in blockchain projects.
• He is an Angel investor in NEO with over 17 years of field experience in mobile internet in China

Zhiyun Qian

• Cybersecurity expert who discovered serious vulnerabilities in Linux, Android and TCP/IP
• Assistant Professor at University of California Riverside

Additional Resources:

• Github — QuarkChain
• For a in depth code review check out Andre Cronje’s breakdown: