C++的差分隐私laplace噪声实现

 

　　

double noisyCount(int sensitivity，double epsilon)
{
    //assert(epsilon > 0);
    int d = rand();

    if(d == 0)
        d++;
    else if(d == RAND_MAX)
        d--;

    double uniform = (double)d/RAND_MAX- 0.5;
    double s=(double)sensitivity;
    return s / epsilon * Math::Sign(uniform) * Math::Log(1 - 2.0 * Math::Abs(uniform));
}