DescriptionQuarkchain is an innovative permissionless blockchain architecture that aims to meet the global-wise commercial standard. It provides a secure, decentralized and scalable blockchain solution to deliver 1,000,000+ on-chain TPS. The main features of Quarkchain are: 1. 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 that confirms the blocks from the first layer. The second layer is flexible to be resharded as needed without changing the root layer. 2. 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. 3. 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. 4. 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. 5. Simple account management: There is only one account needed for the entire blockchain (shards) in QuarkChain. All cryptocurrencies from different shards are stored in one smart wallet.