Title: GESKI: a gas efficient structure for processing spatial keyword queries with hybrid storage architecture

Authors: Muhammad Kashif Azhar; Bin Yao; Muhammad Imran; Waqas Ali

Addresses: Department of Computer Science and Engineering, Shanghai Jiao Tong University, Shanghai, China ' Department of Computer Science and Engineering, Shanghai Jiao Tong University, Shanghai, China; Hangzhou Institute of Advanced Technology, Hangzhou, China ' Department of Computer Science and Engineering, Shanghai Jiao Tong University, Shanghai, China ' Department of Computer Science and Engineering, Shanghai Jiao Tong University, Shanghai, China

Abstract: Spatial keyword queries are ubiquitous, and they play an essential role in a myriad of location-based services (LBS) and geographic information systems (GIS). In recent years, blockchain is shifting trends towards decentralised LBS and GIS applications due to its immutability and traceability by making these applications more secure and trustworthy. However, the integration of spatial keyword data in blockchain poses different challenges like storage limitations and performance bottlenecks. To overcome these challenges, this paper proposes a Gas Efficient Spatial Keyword Index (GESKI), which is a smart contract-based implementation of Merkle Patricia Trie, and quad tree. The GESKI provides a gas efficient cost model for storing and processing of spatial keyword data. To enhance storage capacity, we also implemented a smart contract enabled hybrid storage solution by combining on-chain and off-chain paradigms. We performed multiple experiments for comprehensive evaluation over spatial keyword queries, and the results show that GESKI is able to achieve a 7-10× improvement in terms of gas efficiency in different settings, which demonstrates the efficiency and effectiveness of our proposed method.

Keywords: blockchain; smart contract; spatial keyword queries; hybrid storage.

DOI: 10.1504/IJICS.2025.148858

International Journal of Information and Computer Security, 2025 Vol.28 No.2, pp.181 - 204

Received: 05 Jan 2024
Accepted: 09 Jul 2024
Published online: 29 Sep 2025 *

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