Resumen
With the advent of cloud computing, more and more users begin to outsource encrypted files to cloud servers to provide convenient access and obtain security guarantees. Searchable encryption (SE) allows a user to search the encrypted files without leaking information related to the contents of the files. Searchable symmetric encryption (SSE) is an important branch of SE. Most of the existing SSE schemes considered single-user settings, which cannot meet the requirements for data sharing. In this work, we propose a multi-user searchable symmetric encryption scheme with dynamic updates. This scheme is applicable to the usage scenario where one data owner encrypts sensitive files and shares them among multiple users, and it allows secure and efficient searches/updates. We use key distribution and re-encryption to achieve multi-user access while avoiding a series of issues caused by key sharing. Our scheme is constructed based on the index structure where a bit matrix is combined with two static hash tables, pseudorandom functions and hash functions. Our scheme is proven secure in the random oracle model.