Forward secure searchable encryption using key-based blocks chain technique

Searchable Symmetric Encryption (SSE) has been widely applied in the encrypted database for exact queries or even range queries in practice. In spite of it has excellent efficiency and complete functionality, it always suffers from information leakages. Some recent attacks point out that forward privacy is the vital security goal. However, there are only several schemes achieving this security. In this paper, we propose a new flexible forward secure SSE scheme referred to as “FFSSE”, which has the best performance in literature, such as fast search operation, fast token generation and O(1) update complexity. It also supports both add and delete operations in the unique instance. Technically, we exploit a novel “key-based blocks chain” technique based on symmetric cryptographic primitive, which can be deployed in arbitrary index tree structures or key-value structures directly to guarantee forward privacy.