SBLWT: A Secure Blockchain Lightweight Wallet Based on Trustzone

Due to the increasing total value of the digital currency, the security of encryption wallet is becoming more and more important. The hardware-based wallet is safe, but it is inconvenient because users need to carry an additional physical device, the software-based wallet is convenient, but the safety cannot be guaranteed. All these wallets need to synchronize the blockchain, while most current mobile devices do not have the capability to store all blocks. To solve these problems, mobile devices can use simplified payment verification (SPV). Nevertheless, in existing methods, there is no good way to protect the verification process of the transaction. In this paper, we design a secure blockchain lightweight wallet based on Trustzone to protect SPV. It is more portable compared with the hardware wallet, and safer than the software wallet. Through the isolation, it can also protect the private key and the wallet's address from being stolen by the attackers no matter whether the Rich OS is malicious or not. Meanwhile, it can protect the verification process by verifying transactions in the secure execution environment (SEE), and keep the local block headers unreadable directly from the Rich OS through encryption. We deploy it on the RASPBERRY PI 3 MODEL B development board. The result of the experiment shows that it has little impact on the system.