A method of preserving privacy for usage of a lightweight blockchain client in a blockchain network includes using, in a full blockchain node of the blockchain network, a secure software guard extensions (SGX) enclave. A request is received from the lightweight blockchain client for a setup of a secure network connection. A client unique ID is received from the lightweight blockchain client, and is acknowledged following a successful attestation by the lightweight blockchain client. A request is received from the lightweight blockchain client for transaction(s)/address(es) of the lightweight blockchain client. The SGX enclave loads and searches unspent transaction outputs (UTXO) from a memory of the full blockchain node and sends a response to the request from the lightweight blockchain client for the transaction(s)/address(es) based on a match from the searching the UTXO. The secure communication is then terminated with the lightweight blockchain client.