Where are my containers?

During the investigation of the security within a seaport ecosystem it turned out that the communication channels between major players, like shipping lines, terminal operators, customs or a Port Community System, may be open gateways for cyber threats. The trust between players is limited as they are frequently competitors, yet communication if not done in an ad hoc manner often occurs without much provision for confidentiality and integrity.
For container shipment the state of containers is crucial information for several players. The players usually operate their own local databases and exchange state changes of containers via bilateral peer-to-peer communication that may easily lead to inconsistent information. Since blockchains are a promising evolving technology to ensure integrity and accountability, we propose and try out a blockchain based replacement for classical databases like those for containers. The challenges of blockchain solutions are confidentiality and global access control. In our prototypical implementation for container tracking, we strongly address role-based and attribute-based access control for multitenancy.