A Layered Searchable Encryption Scheme with Functional Components Independent of Encryption Methods

Algorithm 6

Search (asymmetric): Search(𝐾_pub,𝐶,𝐺,𝐿,𝑇).

Input:

(1) 𝐾_pub: the user's public key.

(2) 𝐶: encrypted documents.

(3) 𝐺: global searchable structures 𝐺=(𝐺₁,…,𝐺_𝑛).

(4) 𝐿: local functional structures 𝐿=(𝐿₁,…,𝐿_𝑛).

(5) 𝑇: the search tokens 𝑇=(𝑡₁,…,𝑡_𝑜).

Output: matched documents 𝐶^′=(𝑐₁,…,𝑐_𝑚).

Method:

(1) compute 𝐶^′←ASE·Search(𝐾_pub,𝐶,𝐺,𝑇). Let 𝐶^′=(𝑐₁,…,𝑐_𝑥).

(2) for each 𝑐_𝑖∈𝐶^′ and the functional structure 𝐿_𝑖 (1≤𝑖≤𝑥) do

(3)  let 𝐺_𝑖=(𝑠_𝑖1,…,𝑠_𝑖𝑎) denote the searchable encryptions of 𝑐_𝑖,

   where 𝑎 is the number of keywords in 𝑐_𝑖.

(4)  for each 𝑡_𝑦 (1≤𝑦≤𝑜) in 𝑇  do

(5)   find 𝑠∈𝐺_𝑖 where ASE·Test(𝐾_pub,𝑠,𝑡_𝑦)==𝑦𝑒𝑠.

(6)   compute 𝑣_𝑖𝑦←𝑓_ℎ(𝑠).

(7)  end for

(8)  let 𝑉_𝑖=(𝑣_𝑖1,…,𝑣_𝑖𝑜), 𝐿_𝑖=(𝐿¹_𝑖,…,𝐿^𝑒_𝑖).

(9) end for

(10) for each functional component 𝙵𝙲_𝚓 (1≤𝑗≤𝑒) do

(11)  let 𝐶^′=(𝑐₁,…,𝑐_𝑥), then the corresponding 𝐿^′=(𝐿₁,…,𝐿_𝑥)

  and 𝑉_𝑇=(𝑉₁,…,𝑉_𝑥). Let 𝐿^𝑗=(𝐿^𝑗₁,…,𝐿^𝑗_𝑥).

(12)  compute 𝐶^′← 𝙵𝙲_𝚓·Filter(𝐶^′,𝐿^𝑗,𝑉_𝑇).

(13) end for