Investigating the Role of Post-Quantum Cryptography in Enhancing Blockchain-Based Geospatial Data Exchange

Abstract. The rapid expansion of geospatial data from satellite images, IoT sensors, and location services has created significant opportunities for applications such as urban planning, environmental monitoring, and defence intelligence. However, the sensitive nature of geospatial data sets poses serious security challenges, including unauthorised access, data manipulation and the emerging threats of quantum computing. Traditional cryptographic systems such as RSA and Elliptical Curve Cryptography may be vulnerable to quantum attacks, which highlights the need for quantum-resistant security mechanisms. This paper proposes a hybrid architecture that integrates post-quantum cryptography, blockchains, and decentralised storage to ensure a secure and scalable exchange of geospatial data. The proposed system combines AES-GCM for high-performance symmetric encryption with Kyber-based key encapsulation on a lattice basis to provide quantum-proof key protection. Encrypted geo-spatial data is stored off-chain using the IPFS (Interplanetary File System), while metadata and access control policies are managed by smart contracts on private Ethereum blocks. The architecture is implemented with FastAPI back-end services, cryptographic microservices, and a web interface to interact with the user. Experimental evaluation shows a stable performance across different geospatial file sizes, with low standard deviations indicating a consistent required computing power. The results highlight the feasibility of integrating post-quantum cryptography with decentralised technologies to enable the sharing of geospatial data in a secure, scalable and resilient way in the future.