@unpublished{borgs2018private, author = {Borgs, Christian and Chayes, Jennifer and Smith, Adam}, title = {Private Algorithms Can Always Be Extended}, year = {2018}, month = {November}, abstract = {We consider the following fundamental question on ε-differential privacy. Consider an arbitrary ε-differentially private algorithm defined on a subset of the input space. Is it possible to extend it to an ε′-differentially private algorithm on the whole input space for some ε′ comparable with ε? In this note we answer affirmatively this question for ε′=2ε. Our result applies to every input metric space and space of possible outputs. This result originally appeared in a recent paper by the authors [BCSZ18]. We present a self-contained version in this note, in the hopes that it will be broadly useful.}, url = {http://approjects.co.za/?big=en-us/research/publication/private-algorithms-can-always-be-extended/}, }