Practical Multiuser Dynamic Searchable Symmetric Encryption With Collusion Resistance
Chenbin Zhao, Ruiying Du, Jing Chen, Kun He, Li Xu, Jiguo Li · IEEE Transactions on Reliability · 2025
As data sharing becomes more prevalent, there is growing interest in multiuser dynamic searchable symmetric encryption (MU-DSSE). It enables multiple authorized users to search the encrypted database while safeguarding data privacy. However, most existing schemes are inefficient due to complex computation operations and unaffordable storage burdens. In addition, some are susceptible to collusion attacks between cloud server and compromised users, leading to the leakage of search privacy from other legitimate users. To overcome these challenges, we propose a practical MU-DSSE scheme featuring an unlinkable key derivation mechanism to thwart collusion attacks. Moreover, the MU-DSSE scheme ensures both forward and backward securities in the dynamic setting. To enhance efficiency, we introduce an innovative identity-based key encapsulation mechanism for distributing authorization information to multiple users, significantly optimizing computation and storage costs on user sides and the data owner. Furthermore, we provide the formal security proof and performance analyses. The experimental results demonstrate that MU-DSSE incurs the constant-size storage cost on user sides and the data owner, and outperforms the existing schemes in practice.