Sharing of data between researchers can benefit data owners, data users, and overall the scientific community. However, sharing presents challenges such as data owners losing control of their data. In this paper we explore a blockchain-based tool for managed data sharing. We present a concrete demonstration where data owners can control access to their data. We also discuss the possibilities and challenges of such an approach. Possibilities include flexible data storage and data access tracing without relying on a trusted third party. Challenges include identity verification, ease of use and blockchain transaction costs.