Noise Tuning Tool

This tool is designed to help choose user utility function U(r) parameters for the generation of release probability mass P(r) that affords ε-differential privacy.

Utility Function

The noise utility at point r between r_min and r_max given real count c is given by the function U defined as:

U(r,c) = b|r - c|^a

Parameters

Double-click values to edit or select a preset, then click "Recompute".

c	ε	α⁺	β⁺	α^-	β^-	r_min	r_max

Presets:

Computed values

A random deviate r is chosen with probability P(r). Let Δ be the sensitivity of U, i.e. the max change in U for any r between r_min and r_max resulting from a unit change in c. Then we have that releasing r affords ε = 2ηΔ differential privacy. For a chosen ε, we compute the needed η. Furthermore, we compute the discrete distribution P(r) and its mean and variance. Finally, a few random deviates are chosen using P(r). Click the "Recompute" button to generate a new random deviates and refresh the plots.

η	Variance	Mean	Random Deviates

Utility Shape

Probability Mass