Search Result Verifiability in Multi-User Dynamic Searchable Symmetric Encryption

Dynamic Searchable Symmetric Encryption (DSSE) enables a single user to retrieve and update an encrypted database stored on an external server without decryption. Multi-User DSSE (MUDSSE) enables a data owner to give access rights to multiple users, and the users perform keyword searches on the encrypted database. This paper shows a concrete construction of verifiable MUDSSE, which allows users to verify the correctness of their search results, for the first time. Our construction is achieved by extending the method proposed by Bost et al. (ePrint 2016) for converting a (single-user) DSSE into a verifiable one to a method applicable to MUDSSE.