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${\cal K}$ is $\varepsilon$-differentially private if for every pair of databases $x_1,x_2\in {\cal X}$ (not necessarily adjacent), and for every $z\in Z$, we have: 
$$p(Z=z|X=x_1) \le e^(\varepsilon h(x_1,x_2)) p(Z=z|X=x_2)$$
where $ h(x_1,x_2) $ represents the Hamming distance between  $x_1$ and $x_2$
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