Examination of Post-Processing as a Composition Technique
Post-processing refers to applying additional computations or
transformations to the output of a differentially private mechanism.
While basic differential privacy ensures that the original analysis
outcome is protected, post-processing can potentially introduce
additional privacy loss. This makes it necessary to analyse the combined
effect of the initial mechanism and the post-processing step to ensure
that the overall privacy guarantees remain intact.
In some cases, post-processing can improve utility without significantly
compromising privacy. However, careful consideration is required to
ensure that the post-processed output still adheres to privacy
constraints.