FORWARD SECURE MULTI-ACCESS LEVEL SEARCHABLE ENCRYPTION SCHEME

This paper comprehensively analyzes existing dynamic searchable encryption schemes. To address the limitations of single-level permissions and identical search results for identical keywords in multi-user scenarios, we propose a forward-secure multi-access level searchable encryption scheme with bilinear mapping. The key distribution authorization was realized by bilinear, and the trapdoor was generated together with the proxy server to ensure the security of the trapdoor. User permissions were embedded into the index structure, enabling different search results for identical keywords across varying access levels. The unidirectional property of chained index structures guaranteed forward security. The security and efficiency of the scheme were analyzed, and it was proved that the scheme satisfied the security under the provable security theory.