许多政府在探讨如何更好地应用区块链技术。本文提出了采用区块链架构，设计和实现基于角色的访问控制，以支持对访问权限和访问记录进行监管，提高政府部门之间政务数据共享的安全性。本论文设计了两类智能合约，用于实现对访问权限的定义、查询和监管，分别采用公共和私有事务机制存储于区块链中。第一类智能合约用于存储访问权限、系统中用户和组织的信息，允许特定角色创建、编辑和修改维护智能合约；第二类用于存储数据访问的事务信息，可用于对于互操作的历史记录进行监管。论文采用Quorum区块链网络实现了所提出的体系架构。区块链网络中包含不同的政府组织节点，并由特定节点实现访问控制的监管功能。Quorum采用联盟链，只有授权节点才能访问区块链网络。政府部门或组织的联盟节点之间采用对等网络（peer-to-peer）结构，并采用IBFT 共识算法。基于所提出的体系架构，论文实现了基于Quorum区块链网络的原型系统RBAC-Gov，并构建了一个分布式应用演示系统。实验结果表明，本论文提出的解决方案及RBAC-Gov系统具备可行性。

Many governments are trying to exploit ways how to use blockchain technology. In this thesis, a role-based access control for government data sharing system using blockchain (RBAC-Gov) architecture is proposed, which allows different government organizations a secure way to share information based on access rights, also allowing the supervision of queries. This thesis focuses on the smart contract design and the blockchain network design for achieving a blockchain-based role-based access control system for government use. The proposed architecture in this thesis contains a design of 2 smart contracts for achieving the role-based access control and the supervision of queries, which are stored in the blockchain using public and private transactions. The first designed smart contract is used for storing the information of the access rights, the users of the system, and the organizations taking part in the system, also allowing the modification of them. The second designed smart contract contains information about a query that was performed in some organization's database. These smart contracts are used for the supervision of queries in the proposed architecture. The Quorum blockchain network of the proposed architecture consists of different government organizations, which form a peer-to-peer blockchain network without relying on any third parties. Some of those organizations act as the supervisors of the access control system. The Quorum blockchain network of the proposed architecture is a consortium blockchain that uses IBFT consensus and only authorized nodes are allowed to join the blockchain network.This thesis contains a demo implementation of the proposed RBAC-Gov architecture. The demo implementation includes a decentralized application and a Quorum blockchain network. It was implemented to show that the proposed RBAC-Gov architecture of this thesis could also be implemented.