  A blockchain is a distributed ledger forming a distributed consensus on a
history of transactions. It is the underlying technology for the Bitcoin
cryptocurrency, but there are many applications beyond the financial sector.
With built-in security and removal of the need for third party trust,
blockchain has started to see some use within contract applications among other
things. In this paper, we present the design and implementation of a
permissioned-based blockchain third party consent management system, whose
policy can be decided by a government agency. We have constructed a proof of
concept implementation using Hyperledger Fabric to provide a service that
allows end-users to control and consent to who manages their private
information. We believe our solution meets the guiding principles of EU General
Data Protection Regulation or GDPR. While our performance and usability
evaluation are limited, our solution design and its implementation meet the 7
foundational principles of privacy by design.
