Eywa CDP Introduction
Cross-chain Data Protocol allows dApp developers to link smart contracts from different networks to each other. This enables dApp developers to implement completely new mechanics in the NFT, DAO, DeFi, GameFi, and other markets.
The Cross-chain Data Protocol is based on a decentralized node-oracle network. The network operates on the Roll-DPoS consensus. Transmitted data is cryptographically verified by the decentralized oracle-node network using BLS cryptography and written to the internal Eywa blockchain. Cross-chain call validators are regularly replaced based on reputation and collateral information. This ensures high security and immutability of transmitted data.
All cross-chain transactions are performed via special smart contracts, whose events are listened to by oracle nodes. To send a cross-chain transaction, one must specify a unique identifier of the destination network, the address of the target smart contract and attach the transmitted data as a byte object. Once written to the EYWA blockchain, the cross-chain call can be sent to the destination network within a few epoch.
The key element of Eywa is a data transfer protocol among blockchains - the Eywa Cross-chain Data Protocol (Eywa CDP). This technology allows to move data among smart contracts on different networks in a reliable and secure manner. All Eywa ecosystem products use the Eywa CDP as a transport layer among blockchains.
Why is the transport layer among blockchains needed?
Currently, blockchains are isolated systems within which projects' ecosystems are being formed. An availability of the transport layer linking blockchains opens up a broad spectrum of possibilities:
Fast liquidity transfer among blockchains. Every day new DeFi projects appear in different blockchains, offering earning mechanisms for their users. In the rapidly changing market conditions, for users, it is important to be able to quickly move their assets among networks in order to effectively use their investment opportunities;
Transfer of digital property objects among blockchains. The transfer of digital property objects in a form of NFTs among different ecosystems is a crucial aspect for a mass adoption of blockchain technologies in the fields of intellectual property law and the gaming industry;
Development of cross-chain applications. The transport layer for data exchange among blockchains will allow developers to create a unified architecture composed of smart contracts on different blockchains. This will allow to implement fundamentally new mechanics for the Web3 users that were not possible before.
Eywa Cross-chain Data Protocol
The Eywa CDP solves the problem of transferring data among blockchains by creating the intermediate blockchain where the cross-chain calls validated by the decentralized network are stored. The Eywa Cross-chain Data Protocol consists of two parts: Eywa's decentralized Oracle Network and a set of smart contracts in every blockchain.
Eywa Oracle Network
Many Eywa oracle nodes compose the distributed network that processes cross-chain calls among blockchains. Each cross-chain call is signed by a unique collective signature of validator nodes selected from the total number of Eywa oracle nodes. The signed cross-chain call is recorded on the Eywa blockchain.
To prevent malicious actions by nodes, each oracle node must put a deposit into the special smart contract in Eywa tokens. In case if the node performs its job properly, it receives Eywa tokens. If the node takes malicious actions, then its collateral will be slashed.
The additional mechanism that ensures network security is the epoch. The set of validator nodes changes every four hours according to a special algorithm, which significantly reduces a feasibility of malicious nodes to influence the consensus result of the Eywa oracle node network.
CDP smart-contract infrastructure
The Eywa CDP smart contracts are present on every blockchain supported by the protocol. They serve as a linkage among blockchains and oracle nodes. The main tasks of smart contracts are as follows:
To notify the oracle node network about the new cross-chain call;
To check the correctness of the cryptographic signature of the cross-chain call when it comes to the destination network;
The contracts located in governance chain that manage the consensus: lottery contract that manages the choice of the validators, contracts that govern staking, rewards and slashing.
Step-by-step explanation
Let us describe the cross-chain call scheme from Blockchain A to Blockchain B step-by-step:
Step 1. The user packs the data into the transaction that he /she wants to send to another blockchain and sends the transaction to the special smart contract located in the source blockchain;
Step 2. The smart contract notifies oracle nodes about the new cross-chain call;
Step 3. Relay nodes sign the cross-chain call and write it down into their internal blockchain;
Step 4. The third party takes the signed cross-chain call and sends it to the smart contract in the destination network;
Step 5. The Eywa smart contract in the destination network checks whether the cross-chain call was signed exactly by the validator nodes;
Step 6. If the signature is valid, it pushes the data further into the destination smart contract.
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