F

A collection of files that are outsourced represents a collection of n data files.

W

A collection of different keywords that are extracted from the document collection F, representing a collection of p words.

I

Index for the establishment of a fuzzy keyword search for privacy preserving.

Tw

After user input search keywords w, the search request is generated by the one-way function, that is Trapdoor.

FID_wi

The file set F contains an ID collection of documents of keywords w_i or near w_i-syllable word or synonym.

f(key,・),g(key,・)

Pseudo random function (PRF), defined as {0, 1}* × key→ (0, 1).

Enc(key,・)

Dec(key,・)

Symmetric key encryption/decryption function based on semantic security.

ED(w₁, w₂)

A description method of string similarity. For two words w₁ and w₂ in the two to achieve the increase of the minimum number of the required to convert, modify or delete the operation of the characters. For a given word w and integer d, with S_w,d representing similar thereto word w’, to meet the.

SP_w,d

The fuzzy Pinyin of keywords w corresponding to the keyword set. For the given Chinese keywords w and integer d, the Pinyin PY_w corresponds to the fuzzy tone set, to meet with the edit distance of keywords w’s Pinyin that is less than d for all similar Pinyin keywords set expressed as. For any, the pinyin of is represented as.

SYw

A set of keywords synonymous with keywords w. different keywords set. Describing the same thing in a language are converted into another language, generally corresponding to the same keywords w_e, which is called set, as a synonym set for keywords w, among them the, syn() is synonymous conversion function. This paper uses Chinese and English to achieve the conversion.

Fuzzy keyword search

A collection consisted of n encrypted data files and different predefined keywords set are given, search keywords w and d input and after the implementation of the synonymous keyword search it will return to the ID file set {FIDw_i,}, in which, or.

History

The interaction between the user and the cloud server, which is composed of F and a group of keywords, is expressed as.

View

According to the secret key K, historical records Hq given, cloud servers can only see encrypted history that is the view of Vk (Hq). It includes index I of document collection f, query keywords trapdoor. Among them and., encryption file set C , is expressed as.