Poster
in
Workshop: Theory and Practice of Differential Privacy
Privacy Amplification by Bernoulli Sampling
Jacob Imola · Kamalika Chaudhuri
Balancing privacy and accuracy is a major challenge in designing
differentially private machine learning algorithms. One way to improve this
tradeoff for free is to leverage the noise in common data operations that
already use randomness. Such operations include noisy SGD and data subsampling. The additional
noise in these operations may amplify the privacy guarantee of the overall
algorithm, a phenomenon known as {\em{privacy amplification}}. In this paper, we
analyze the privacy amplification of sampling from a multidimensional
Bernoulli distribution family given the parameter from a private
algorithm. This setup has applications to Bayesian inference and to data
compression. We
provide an algorithm to compute the amplification factor, and we
establish upper and lower bounds on this factor.