Tree-Based Public Key Encryption with Conjunctive Keyword Search

Table 1

Comparison between previous searchable encryption schemes and ours.

Ref.	Search function	Index structure	Setting	Additional special abilities
Ours	Conjunctive keyword search	Tree-based index	Public key	—
[5]	Conjunctive keyword search	Forward index	Public key	—
[6]	Conjunctive keyword search	Forward index	Public key	—
[7]	Boolean keyword search	Forward index	Public key	—
[8]	Conjunctive keyword search	Forward index	Public key	—
[9]	Conjunctive keyword search	Forward index	Public key	Verification for query results
[10]	Conjunctive keyword search	Forward index	Public key	Resistance for KGA
[11]	Single keyword search	Forward index	Public key	Access control
[12]	Single keyword search	Forward index	Public key	Certificateless encryption
[13]	Conjunctive keyword search	Hidden structure	Public key	—
[14]	Rank search	Tree-based index	Symmetric key	—
[15]	Rank search	Tree-based index	Symmetric key	—
[16]	Rank search	Tree-based index	Symmetric key	—
[17]	Rank search	Inverted index	Symmetric key	—
[18]	Rank search	Inverted index	Symmetric key	—

The additional special ability means that this scheme owns some extra security mechanism. KGA is the abbreviation of keyword guessing attack. Rank search is that the search result will be ranked before returning to the data users.