QuarkChain — A High-Capacity Peer-to-Peer Transactional System?
1. What is QuarkChain?
QuarkChain is a high-throughput blockchain that aims to achieve millions of transactions per second (TPS). The high-capacity system will solve the scalability problem that current main blockchains are facing.
This problem is so urgent that bitcoin community can’t wait to reach an agreement. Different solutions compel the community to split through a controversial hard fork. (As a reference, Bitcoin blockchain only offers around 4 TPS.)
2. What are QuarkChain tokens?
QuarkChain tokens (QKC) are ERC-20 compatible tokens distributed on the Ethereum blockchain. After our mainnet is launched, the ERC-20 tokens will be converted to mainnet’s token by premining. Future QKCs will be produced by miners.
3. What DApps will QuarkChain support?
QuarkChain welcomes various DApps, especially those demand high transaction rates: advertisement, IOT ( internet of things) , AI and big data, game, peer to peer sharing economy, etc. Today, lots of dApps are waiting for a more reliable and scale foundation to begin with, QuarkChain will become a perfect choice.
4. It seems there are several ongoing projects claim they can achieve high TPS, what makes QuarkChain different?
Only looking for a high TPS network is not a new story. Every year, well-known payment networks, e.g., Alipay, can reach 200K peak TPS. The challenge of this project is to obtain an extremely high TPS while maintain the network’s decentralization and security at the same time. Scalability, decentralization, and security have very different conditions and requirements, many methods could not take care all of them. QuarkChain system increases throughput while maintaining decentralization and security.
5. Why QuarkChain can realize this (high TPS)?
This is a result achieved by several cool features of QuarkChain jointly. They are:
Reshardable two-layered blockchain: QuarkChain consists of two layers of blockchains. We apply elastic sharding blockchains (shards) as the first layer, and a root blockchain as the second layer that confirms the blocks from the first layer. The second layer is flexible to be resharded as needed without changing root layer.
Guaranteed security by market-driven collaborative mining: To ensure the security of all transactions, a game-theoretic framework is designed for incentives, where at least 50% of overall hash powers are allocated to the root chain to prevent double spending attack on any transactions.
Anti-centralized horizontal scalability: In any blockchain network with a high TPS, a super-full node can be extremely expensive, which encourages centralization. In contrast, QuarkChain allows multiple cheap nodes forming a cluster to replace a super-full node.
Efficient cross-shard transactions: Cross-shard transactions in QuarkChain can be issued at any time, and confirmed in minutes. The speed of cross-shard transactions increases linearly as the number of shards increases.
Simple account management: There is only one account needed for the entire blockchains (shards) in QuarkChain. All cryptocurrencies from different shards are stored in one smart wallet.
6. What is QuarkChain’s relationship with DAG or Tangle technology?
QuarkChain itself can be treated as a well-structured DAG: given two DAGs of QuarkChain, we could easily tell which one should be appended after thanks to QuarkChain’s root chain. This allows QuarkChain to inherit a lot of benefits from both Bitcoin/Ethereum and general DAG technique. E.g., the consensus of QuarkChain and its threat model can be easily derived/analyzed following those of Bitcoin/Ethereum, while QuarkChain achieves high throughput similar to general DAG.
7. How could QuarkChain scale from 10K TPS to 1M TPS?
QuarkChain aims to deliver hundreds of thousands or millions of transactions per second in a few years. Note that these numbers are capacity of QuarkChain system, i.e., peak performance, rather than average TPS in production, which is generally much smaller. When achieving the peak numbers, we need to consider several bottleneck factors. They could overcome the bottlenecks by:
1) CPU: Most consuming part of CPU is validation of the transactions. Our experiment shows that single core could validate several thousands of transactions per second (e.g., AWS EC2 c5 instances), and QuarkChain’s capacity could scale almost linearly as # of cores increases thanks to sharding (e.g., AWS EC2 c5 instances could have at most 72x cores). In addition, existing research shows that with GPU optimization, the cryptographic operations by GPU could be more than 5x faster than that of CPU. With fully optimization in CPU/GPU, this should enable us to validate 100+K transactions per second in single node. With clustering feature enabled, QuarkChain should be able to achieve 1+M TPS with more than 10+ machines in the cluster.
2) Network bandwidth: Suppose a transaction size is about 250 bytes, 100+ TPS takes about 2 Gbps network bandwidth. This is considerable high at the moment, but such network bandwidth will be gradually available in the next few years with new network technologies such as Fiber.
3) In addition, another bottleneck of QuarkChain is the block size limit of root chain. Consider 8MB root block size limit, 256 bytes per transaction, and 1M per block size in shard with 128 bytes of block header, a root block could confirm 8M / 128 * 1M / 256 = 256M transactions. Given that the root block interval is 150 sec, then the maximum transaction per second supported by QuarkChain will be 1.7+ M TPS.
8. Team and advisors?
The team consists of 10 members, with the following being the key members of the team:
Qi Zhou, Founder — PhD in Electric and Computer engineering with 5 years’ experience in engineering and software engineering with the most recent being with Facebook as a software engineer.
Zhaoguang Wang, Software Engineer — 7 years’ experience in software engineering with tech giants such as Facebook, Instagram, and Google.
Xiaoli Ma, Research Scientist — Professor at Georgia Institute of Technology. PhD in electrical engineering and 7 years’ experience in the tech industry with the most recent being the CTO of Ratrix Technologies.
Yaodong Yang, Research Scientist — PhD in engineering, and a Tenure Track Professor at Xi’an Jiaotong University, and co-founder of Demo++ Technological Incubator.
They also have 6 advisors including Bill Moore, Chief Engineer for Storage at Sun Microsystems, Arun G. Phadke, Virginia Tech Professor, Zhiyun Qian, cyber security expert, among others.
9. Conclusion 9/10
QuarkChain has outstanding advisors and a good team. It has already launched an MVP, which shows 2K TPS (transactions per second), and QC plans to have 100K TPS by the end of this year. QuarkChain has already raised $16M out of a projected $20M from private sales. Competitors on the current market indicate the huge potential growth for QuarkChain tokens. The hype rate is very high. I have only deducted some points because it seems that new, high-speed blockchains appear every month, and the industry is getting more saturated.