Hajautettu tiedostojenjako mobiililaitteilla

Most applications and services rely on central authorities. This introduces a single point of failure to the system. The central authority must be trusted to have data stored by the application available at any given time. More importantly, the privacy of the user depends on the service provider capability to keep the data safe. To remove the central authority a decentralized system is needed. Due to the rapid growth of mobile device usage, the availability of decentralization must not be limited only to desktop computers. This thesis examined the possibility to use mobile devices as a decentralized file sharing platform without any central authorities. This was done by implementing a peer-to-peer file sharing mobile application. InterPlanetary File System was selected as the peer-to-peer network. To evaluate the validity of the approach, network usage and power consumption of multiple different devices was measured while the application was running. The results indicate that mobile devices can be used to implement a worldwide distributed file sharing network. However, the file sharing application generated large amounts of network traffic even when no files were shared. This was caused by the chattiness of the protocol of the underlying peer-to-peer network. Consequently, constant network traffic prevented the mobile devices from entering to deep sleep mode. Due to this the battery life of the devices was greatly degraded. Further measurements are needed when the InterPlanetary File System reference implementation is more mature