Phrase Search over Encrypted Data with Symmetric Encryption Scheme

Abstract

We study the case of searching over encrypted data from a remote server. In order to retrieve the encrypted documents that satisfy a client's criteria , a special index must be built and sent by the client together with encrypted documents. A trapdoor will also be produced to offer the privilege to search on the index. In the area of searchable encryption, many works mainly focused on search criteria consisting of a single keyword or conjunctive keywords. Up until now, searching of the exact documents that contain a phrase, or consecutive keywords still remains an unsolved problem.We first define the model of phrase search over encrypted data with symmetric encryption and its security definition based on the latest security definition raised by R. Curtmola. Then we propose a construction for phrase search with symmetric encryption(PSSE), which meets the functionality of searching a phrase over encrypted documents securely and efficiently. The computing complexity of our scheme when performing a query is linear in the size of the phrase, and at a moderate communication cost between server and client as well. In addition, we prove that our scheme achieves non-adaptive security.

Generic Adaptively Secure Searchable Phrase Encryption

“…An early construction of phrase queries is due to Tang et al [21]. Their construction operates as a twophase protocol.…”

“…Often times a system that provides security in the presence of adversaries that lie about the number of results are called verifiable. Loosely speaking, their construction combines ideas from [21], which uses essentially a hybrid Merkle tree [15], and [6]. In particular, they replaced the first phase of the scheme of [21] with the verifiable keyword index of [6], and modified the second phase of [21] to include verification.…”

“…In particular, they replaced the first phase of the scheme of [21] with the verifiable keyword index of [6], and modified the second phase of [21] to include verification. These changes make both phases of the scheme of [21] verifiable. They showed that the resulting construction is CQA1 secure.…”

“…-It operates using a single round of communication between the client and cloud to retrieve matching documents. This is a substantial improvement over the existing multi-round systems of Tang et al [21] and Kissel and Wang [13]. -It supports parallel processing of queries.…”

“…Recent work has provided the primitive with more expressive queries. There are now SSE systems that support Boolean queries [5], fuzzy keyword queries [14], and phrase queries [13,21] (our focus).…”