The Technical Structure of Qitmeer
Qitmeer network is a payment network infrastructure using BlockDAG technology, which is based on decentralized distributed ledger technology.
Qitmeer network structure is divided into four layers from the bottom to top: Network Layer, Data Layer, Token Layer, Payment Layer.
Network Layer
Qitmeer is a value transmission network with extremely high performance and security requirements for communication network, some people also position the communication network as layer 0 in blockchain system. Centralized network are at the risk of single node attack. Qitmeer adopts peer-to-peer network (P2P), where all network nodes are fully peer-to-peer, running the same Qitmeer services, and data communicate between these peer-to-peer nodes through P2P network protocol. Qitmeer uses a LibP2P network library with high performance peer-to-peer network data transmission capability and rich peer-to-peer network services.
Data Layer
The core of Qitmeer network is the first layer, the data storage layer, where Qitmeer ensures that the data of each peer node is identical through the MeerDAG consensus protocol.
The MeerDAG consensus protocol used by Qitmeer network is an extension of Bitcoin’s classic Satoshi Nakamoto consensus. Its network node access model and theoretical security are identical to the classical Satoshi Nakamoto consensus. Therefore, Qitmeer nodes are fully decentralized nodes, and motivated by the Proof of Work.
By using MeerDAG protocol, Qitmeer changes the data structure and data organization of the traditional blockchain. The data structure has evolved from the traditional chain model of blocks(BlockChain) to the graph model of blocks(BlockDAG). Data organization has evolved from competitive model(where only winning blocks can be acknowledged) to cooperative model(where concurrent blocks can be acknowledged as long as they are legal). This allows the transaction throughput capacity of the blockchain system to be extended to fundamentally improve the business carrying capacity of the blockchain network. This expansion of Qitmeer network belongs to Layer-1 expansion, i.e., on-chain expansion, which is fundamentally different from Layer-2 expansion of traditional blockchain systems, i.e., off-chain expansion. Layer-1 expansion and Layer-2 expansion are not in conflict with each other. Qitmeer’s Layer-2 payment layer belongs to Layer-2 expansion, which will be mentioned later.
Token Layer
Qitmeer as a financial infrastructure, providing a compliant token infrastructure to provide crypto digital credentials for assets and liquidity.
The Medina network’s token PMEER is based on UTXO model, which is based on the common underlying data model with Umayyad network. Umayyad network token MEER is generated from the block rewards earned by miners mining, and exists as the source of support for the underlying P2P network’s economic model. Token is issued and destroyed by compliance organization.
Qitmeer’s token is different from the ERC20 token of Ethereum’s smart contract systems. Qitmeer’s token layer is an access model where only the compliance organizations can issue and destroy the tokens. Each new token issued on Qitmeer has to pass the network-wide consensus.
It should be noted that Qitmeer’s access mechanism requires a centralized compliance organization to issue and destroy, while the Qitmeer’s underlying data layer and network layer are completely decentralized, which are not contradictory since they are at different layers.
Qitmeer is not a Ethereum-type smart contract system. Qitmeer is a Distributed Ledger Technology（DLT） system that does not provide business-level on-chain computation, and Qitmeer interacts with other smart contract systems in a business-state channel model by recording proofs of commits on the chain, no matter this smart contract system is public BlockChain system such as Ethereum, EOS, or private BlockChain system such as Corda, Hyperleager, Quorum, or a rollup solution based on zero proof of knowledge.
Payment Layer
Qitmeer’s payment layer includes:
1. Native payment model based on layer1, i.e. the UTXO on-chain payment model shared by main network coin MEER and token layer.
2. Off-chain payment model based on layer2.
Native payment model based on layer1
•Native payment model for Umayyad network coin MEER and token layer;
•Cross-chain exchange with traditional cryptocurrency systems represented by bitcoin through the atomic exchange protocol.;
•Cross-chain transactions with ILP compatible systems represented by ripple through the ILP protocol;
•For the smart contract models represented by Ethereum, cross-chain transactions are performed through the atomic exchange model + erc20 token protocol + smart contract model.
Off-chain payment model based on layer2
•Off-chain payment model for Umayyad network currency MEER and token layer through BLOT protocol;
•For the layer 2 payment system of Bitcoin-type system represented by lightning network, cross-chain transactions are performed by compatible with BLOT protocol;
•For relay or star chain models represented by Polkadot and cosmos, cross-chain transactions are performed by constructing Qitmeer’s layer 2 parallel chains or network bridges.
It should be pointed out that Layer-1 and Layer-2 transactions should be distinguished from the transactions in native and token layer. Each single transaction in native and token layer must to be verified on chain, and it belongs to Layer-1 transaction, while most transactions in layer-2 are completed off-chain and do not need to be on-chain.
Qitmeer’s architecture from bottom to top consists of the network layer of P2P protocol, the data layer of MeerDAG consensus protocol, the token layer of UTXO model and on-chain&off-chain double payment layers with high security, high scalability and decentralization, providing technical support for the next generation payment network infrastructure.
