Veronika Polar

Proof-of-work 2.0 (PoW 2.0) is a Proof-of-Work (PoW) based blockchain system which achieves high transaction throughput through a hierarchy of merged mined blockchains, each operating in parallel on a partition the overall application state.

PoW 2.0 is faster, cheaper, and more eco-friendly than PoW. This is achieved by combining merged mining and sharding. In other words, a higher transaction throughput is achieved with the same amount of work by sharing the CPU power across multiple chains .

The major speed advantage of PoW 2.0 over PoW is achieved by using Blake3 hash function instead of SHA-256. Blake3 surpasses SHA-256 speed by over 10x while remaining highly secure. This is possible thanks Blake3 using a tree structure.

Exponential increase of on-chain blockspace in PoW 2.0 transforms the supply curve thus lowering transaction fees.

PoW 2.0 is built more eco-friendly in comparison with PoW by reducing the carbon footptint per transaction. This is achieved with the shared hashrate across several blockchains, highly optimised Blake3 hash function, and higher capacity for transactions.

The token ensures that the netowrk is secure, spam-resistant, and decentralized. The Quai tokenomics are under ongoing development, all further infromation is subject to change before the Quai Network's Mainnet launch.

Quai is a modular blockchain network consisting of three types of chains: Prime, Region, and Zone. At the mainnet launch, the network will start with 13 chains, a single Prime chain, 3 Region chains, and 9 Zone chains, organized in a 3x3 hierarchical structure. It is possible to scale horizontally to add more chains on demand.

The Prime chain addresses the whole network by aggregating and settling state transitions. The chain uses a memory-intensive hashing algorithm that is shared across all chains lower in the hierarchy. The PoW provided by the Prime blocks is used to secure the rest of the network. Out of the three types of chains, the Prime chain has the highest difficulty and the lowest throughput. Each block is approximated at every 15 minutes. It is the only chain that every Quai Network miner mines.

The Region Chains, Cyprus, Paxos, and Hydra, are one tier lower in the network hierarchy than the Prime Chain. The three chains are able to interact natively on the network, but are still separate chains requiring unique mining power. It is possible to add more Region Chains based on user demand in the future.

These chains have a higher throughput and lower difficulty than the Prime Chain, with throughput approximated at about one block every 5 minutes. To mine Quai, the operator must choose one of the Region Chains to mine in addition to the Prime Chain.

Each Region Chain has three subordinate Zone Chains. The naming of the Zone chains goes by adding a number to the Region chain they are under. The Cyprus Region Chain, for example, has three subordinate Zone Chains: Cyprus 1, 2, and 3. Miners choose only one of the chains to mine. Thus, the total minir requirement is the Prime Chain, one of the three Region Chains, and one of the three subordinate Zone Chains.

The Zone Chains have the highest throughput and TPS capacity. Each Zone Chain is expected to output a block every 10 seconds. It is expected that msot network activity will happen on Zone Chains.