Abstract:
To address the limitations in search expressiveness and the inadequacy of verification mechanisms in existing searchable encryption methods, this paper proposes a Verifiable Boolean Searchable Encryption scheme based on Blockchain Index (VBSE-BI). The scheme first constructs a security model supporting verifiable Boolean search and, based on this model, designs an incremental secure index construction method utilizing blockchain storage structures. This approach achieves efficient search while ensuring the tamper-proof nature of the index structure. Moreover, the scheme introduces an efficient dynamic update mechanism for the secure index, effectively avoiding the significant storage and update overhead caused by auxiliary update structures. It meet the integrity verification requirements of Boolean searches, the scheme defines the unforgeability of Boolean search results and proposes a Boolean operation integrity verification algorithm based on bilinear map accumulators and the extended Euclidean algorithm. Security analysis demonstrates that the VBSE-BI scheme can resist dynamic chosen keyword attacks in the random oracle model and satisfies unforgeability under the bilinear
q-strong Diffie-Hellman assumption. Compared with similar schemes, VBSE-BI not only supports more expressive Boolean search statements but also significantly reduces the user's computational complexity to log
n (where
n is the number of keywords). Experimental results show that by optimizing the verification algorithm, the scheme keeps the user’s verification time consistently low (1.0-1.8 s), accounting for only 9.98%-14.03% of the server-side computation time. These findings indicate that VBSE-BI is highly suitable for resource-constrained mobile devices, providing a solid theoretical foundation and efficiency assurance for the practical application of searchable encryption.