Association Rule Hiding Based on Intersection Lattice

Algorithm 1

The AARHIL algorithm.

Input: Original database 𝒟, thresholds 𝜎 and 𝛿, 𝐋(𝒟,𝜎), association rules 𝑅 and sensitive

association rules 𝑆_𝑅,.

Output: Released database 𝒟^′.

Method:

(1)  For each  𝑋⊆𝐋(𝒟,𝜎)  Do

(2)  Calculate 𝑑(𝑋) = |{𝑌∈𝐋(𝒟,𝜎)∣𝑋⊂𝑌}|;

(3)  𝐆_𝐿={𝑋∈𝐋(𝒟,𝜎)∣𝑑(𝑋)≤1};

(4)  𝐂_𝐿=MAX(𝐆_𝐿);

(5)  For  each rule 𝑟∈𝑆_𝑅

(6)  Compute 𝑇_𝑟;

(7)  For each transaction 𝑡∈𝑇_𝑟, compute 𝑤(𝑡);

(8)  Sort 𝑇_𝑟 in descending order of 𝑤(𝑡);

(9)  n_trans = min𝛼(𝑟)−𝜎+1,𝛼(𝑟)−𝛼𝐥_𝑟∗𝛿+1;

(10)  While  n_trans > 0

(11)   Specify victim item 𝐈_victim: 𝐌_maxmin(𝑟)=𝐈_victim,𝑋,𝑍,𝜇;

(12)   k_trans = 𝛼(𝑍)−max𝛼(𝑌)∣𝐈_𝑖,𝑋,𝑌,𝜆∈𝐌_min𝐈_𝑖,𝑋,𝛼(𝑌)≠𝛼(𝑍),𝑋∈𝐂_𝐿 + 1;

(13)   Remove 𝐈_victim from first max{min{𝑘_trans,𝑛_trans},1} transactions in 𝑇_𝑟;

(14)   Remove first max{min{𝑘_trans,𝑛_trans},1} transactions from 𝑇_𝑟;

(15)   n_trans = n_trans − max{min{𝑘_trans,𝑛_trans},1};

(16)   Update 𝐋𝒟^′,𝜎, 𝛼(𝑟), 𝛽(𝑟), 𝐆_𝐿′, 𝐂_𝐿′;

(17)  End

(18) End