Decentralized Blockchain-Based Android App Store with P2P File System

In the Android app store, developers must provide a fee of at least 15% of revenue, and there is no reliable evaluation system for apps, so it can lead to occur the damage with installation of malicious file. Blockchain technology which supports decentralized infrastructure can support transactions between developers and buyers without a central organization. Through the Blockchain technology, the fee-free app trading environment can be created. Ethereum’s smart contract provides permissions through token issuance and can manages the buyers. Therefore, we implement DAS (Decentralized Android app Store) which provides app trading environment without decentralized organization using smart contract. In addition, IPFS is used for APK file sharing to reduce the amount of gas consumed according to the data size. Since only the hash value of the file is registered, not the whole data of the file, it is possible to consume a little constant average gas costs in the process of file registering and purchasing. We implemented as DApp in Ethereum platform. After purchasing the app, it is possible to induce the appraisal of the app reliability through the evaluation permission assigned to the purchaser, and measuring reliability through the purchase rate and the appraisal rate.