In the information realm, loss of privacy is usually associated with failure to control access to information, to control the flow of information, or to control the purposes for which information is employed. Differential privacy arose in a context in which ensuring privacy is a challenge even if all these control problems are solved: privacy-preserving statistical analysis of data. The problem of statistical disclosure control-revealing accurate statistics about a set of respondents while preserving the privacy of individuals-has a venerable history, with an extensive literature spanning statistics, theoretical computer science, security, databases, and cryptography (see, for example, the excellent survey of Adam and Wortmann,1 the discussion of related work in Blum et al.,2 and the Journal of Official Statistics dedicated to confidentiality and disclosure control). © 2011 ACM.