Efficient Two-Step Protocol and Its Discriminative Feature Selections in Secure Similar Document Detection

Algorithm 1

Protocol of SSDD-Base.

Protocol   SSDD-Base

() and are -dimensional vectors owned by Alice and Bob, respectively.

Assume that Alice and Bob maintain the same matrix .

Alice:

  Generate random numbers ;

Compute an -dimensional vector , where; ;

Send to Bob;

Bob:

Compute a scalar value ;

Compute an -dimensional vector , where ;

Send with to Alice;

Alice:

Compute a scalar value ;

Obtain ;     // Note that

 () if then Identify and as a similar one; // = user-specified tolerance