NausiChain: a Mobile Decentralized App Ensuring Service Continuity to University Life in Covid-19 Emergency Times

In an effort to contain the Covid-19 pandemic emergency, nations have sponsored smartphones apps tracing contacts. The ultimate aim is to alert people when a Covid-19-positive has been found and it occurs that they have been in close contact with the positive. In the context of contact tracing, transparency of data gathered is of utmost importance to show beyond doubt that the people privacy is preserved as much as possible. The proposed approach aims at making gathered data publicly available in such a way that anonymity is preserved and stored data are immutable and not owned by a single organization. For this, we equip users in a university environment with an app that reveals their presence as a proximity to a WiFi access point. While the server-side provides location ids to apps, the location history is kept within the app and checks for a possible contact are performed by the app. The server aggregates presence data related to each WiFi access point according to time-slots, and stores these periodically in a blockchain for maximum transparency and immutability. The tests on the developed prototype have shown the accuracy in determining presence data, the feasibility for apps to interact with smart contracts and to have daily presence data stored in a blockchain. The ability to exhibit official and immutable statistics on people gathering at university should be useful to give evidence of the effort to have controlled accesses and gathering avoidance.