A dynamic conjunctive keywords searchable symmetric encryption scheme for multiple users in cloud computing

With the continuous advancement of cloud computing technology, massive amounts of heterogeneous data are being outsourced to cloud servers. Dynamic searchable symmetric encryption (DSSE) is widely used for dynamically updating and searching ciphertext. Although many DSSE schemes have been developed in recent years, few can satisfy the requirement for multi-keyword search. To address this problem, we proposed a novel Dynamic Searchable Symmetric Encryption scheme supporting Multiple users and Multiple keywords (MMDSSE) in this paper, specifically designed for the multi-keyword cloud computing paradigm, while also enabling multi-user search capability. To achieve multi-keyword search, a tag is computed using an iso-or operation that records the relationship between the keyword and identifier. In addition, a unique key is assigned by the data owner to each user with different file access rights. This allows users to gain fine-grained control over the ciphertext, and the essential security properties, including forward and backward privacy, can be achieved accordingly. Furthermore, this scheme is resistant to collusion attacks. Finally, the experiment was simulated on the IDEA platform using the Java language. The experimental results demonstrate that this scheme performs well.