Control access using cross-chain authorization management
After you register a blockchain with the cross-chain data connection service, the service checks all incoming cross-chain messages by default. Only authorized blockchains can connect to your blockchain.
Cross-chain messages in the cross-chain data connection service are of two types. You can manage authorizations for these message types independently in the cross-chain console:
Ledger data access: Grants specific blockchains permission to access basic data on your chain. Basic data includes block headers, full blocks, and full transactions.
Contract message push: Grants specific contracts on other blockchains permission to send data to a contract on your chain using remote contract calls.
For cross-chain ledger data reads, you cannot retrieve basic data from another blockchain unless it grants your blockchain permission. You can access only the data for which you have been granted permission.
For contract message pushes, the permission system checks both the source contract (Contract A) and the destination contract (Contract B) of a cross-chain call. You can make calls only from an authorized Contract A to an authorized Contract B. You cannot use an authorized Contract A to call other contracts on the destination chain. You also cannot use other source contracts to call the authorized Contract B.
In the console, go to View My Permissions to see the permissions that other blockchains have granted to you. Go to Grant Permissions to see the permissions that you have granted to other blockchains.