Blockchain is a digital transaction technology adopt- ing the peer-to-peer concept. The implementation of blockchain on Internet of Things (IoT) aims to secure the possibility of potential attacks against devices or transactions taking place on the IoT sys- tem. At practical levels, blockchain uses smart contracts to auto- mate programs according to predetermined terms and conditions. This research is aimed at implementing an ethereum-based smart home Smart Contract by modifying the device components, dash- boards, and consensus used in Xu et al.’s research. The consensus modification was performed by using Proof of Authority (PoA) aiming to improve block verification performance on the system. The Denial of Service (DoS) attacks and Single Point of Failure (SpoF) vulnerability were performed to evaluate the proposed sys- tem. The evaluation was performed with TCP Flood Attack, with request packets of 81,519 packets on port 8545 and ICMP Floods by sending 11,481,703 PING packets. The attack caused some ap- plication services running on the Ethereum Node 3 to stop, but did not stop the geth application. As for the Single Point of Failure (SPoF) vulnerability, the Ethereum network is still running and there were no obstacles in the mining process or block verification.