With the rapid progress of e-government, a large amount of government information systems has been developed to enhance the operational efficiency of government departments. The increasing number of interdepartmental affairs brings the need of connecting those separately developed information systems by data sharing. The characteristics of blockchain in terms of transparency, security, and traceability make it suitable for interconnection between systems and have garnered much attention from both governments and researchers. This paper analyzes the limitations of existing research on government data sharing using blockchain and proposes a new architecture for Government-to-Government (G2G) data sharing. It leverages the Hierarchical ID-Based Encryption (HIBE) algorithm and the Role-Based Access Control (RBAC) method to transform system operation entities from government employees into government roles, which isolates the original information system from the data sharing system, reducing the costs of applying blockchain techniques. Furthermore, we have designed smart contracts for the proposed architecture and tested them on the Polygon (Ethereum layer 2 network) and Conflux network. The source code for these smart contracts is publicly available.