Data processing method and apparatus based on blockchain, device, and storage medium

A data processing method based on a blockchain, comprising:

• receiving, by a second node device associated with a second blockchain, cross-chain transaction data sent by a cross-chain relay device i of N cross-chain relay devices, the cross-chain transaction data being generated by the first node device by executing a target cross-chain service when determining that the target cross-chain service is legal based on an on-chain service verification contract in a cross-chain transaction protocol, and being forwarded by the first node device to the N cross-chain relay devices, the cross-chain relay device i being configured to transmit the cross-chain transaction data to the second node device in response to determining that the cross-chain transaction data is valid based on an off-chain data verification contract in the cross-chain transaction protocol, the target cross-chain service being associated with a first blockchain maintained by the first node device and the second blockchain, both the first node device and the second node device satisfying the cross-chain transaction protocol, N being an integer greater than 1, and i being an integer less than or equal to N;
• verifying whether the received cross-chain transaction data is legal based on an on-chain service execution contract in the cross-chain transaction protocol, to obtain a data verification result;
• and
• processing the cross-chain transaction data when the data verification result indicates that the cross-chain transaction data is valid.

A data processing method based on a blockchain, comprising:

• receiving, by a cross-chain relay device i of N cross-chain relay devices, cross-chain transaction data sent by a first node device;
• the cross-chain transaction data being generated by the first node device by executing a target cross-chain service when determining that the target cross-chain service is legal based on an on-chain service verification contract in a cross-chain transaction protocol, and being forwarded by the first node device to the N cross-chain relay devices, the target cross-chain service being associated with a first blockchain maintained by the first node device and a second blockchain maintained by a second node device, both the first node device and the second node device satisfying the cross-chain transaction protocol, N being an integer greater than 1, and i being an integer less than or equal to N;
• verifying whether the cross-chain transaction data is valid based on an off-chain data verification contract in the cross-chain transaction protocol;
• and
• sending the cross-chain transaction data to the second node device in response to the cross-chain transaction data being valid, the second node device being configured to process the received cross-chain transaction data in response to determining that the cross-chain transaction data is valid.