4everland storage node portal network design

4everland storage node

Introduce
4EVERLAND The data node layer is based on IPFS Global distributed collaborative node network on , These nodes will form a large IPFS swarm Clustered network . The node program makes use of TEE The technical function of trusted verification , Its purpose is to verify the network access process and program reliability of nodes . Nodes in the whole network need to assume the following roles and functions ：
1.pin Some specific IPFS CID data
2. Verify the program functions of other nodes in the network
3. Regularly report the data storage of nodes
4. Synchronous storage challenges are reported to other nodes and mutually verified whether the reported data is logical. In general , The organization form of nodes is shown in the figure ：

Which consists of ：PoSC of TEE：PoSC：Proof of Storage challenge, Is based on TEE Implemented node verifiable program Data Storage： finger IPFS Storage , The two are binding relationships PoSC Introduce Nodes in the network cooperatively store some characteristics cid data , Therefore need PoSC(Proof of Storage challenge) Mechanism to verify that the node stores these data according to the expected logic . The node will periodically check the stored data of the node according to some preset logic . Each such spot check mechanism will form a report and broadcast it to other nodes throughout the network , Other nodes will verify the validity of the report and store it locally , The following data is an important basis for rewarding and punishing nodes . The network access process of the node. The network access process of the whole node is roughly as follows ：

1. The node program is TEE enclave The region generates a public-private key pair
2. Generate Quote as well as create_attestation_report And send it to IAS Do the authentication
3.IAS Check the result report return
4. After the verification is passed, the mr_enclave Value is compared with the value on the chain check_mr_enclave, If it's not consistent , The program directly returns
5.check_mr_enclave After passing the inspection, store the public and private keys and other information
6. subscribe IPFS Message notification subject
7. On the subscription chain cid Storage contracts , Follow up on these CID Do something about it
8. Listen for messages from other nodes , For example, report synchronization 、 Request of public key 、cid Synchronization message of
9. Different messages are processed according to the predetermined logic , The message field types are roughly as follows

Store reports

The node program listens to storage cid Contract events on the chain , Trigger the corresponding log processing event （ for example insert、remove cid）, Nodes will follow a certain “ cycle ” Generate storage proof report , Report fields include stored cid Sample data 、 Data accuracy and other fields , meanwhile , The node will also report the local key signature to the storage and broadcast it to other nodes throughout the network . The general process is ：

Reference resources

• 4EVERLAND

• Attestation Services for Intel Software Guard Extensions