It is our pleasure to present the proceedings of the 23rd ACM Conference on Computer and Communications Security (CCS 2016), held in Vienna, Austria, on October 24-28, 2016. All papers in the proceedings were subject to a rigorous process of peer review. We received 831 fully reviewed submissions, the largest number of submissions received to date by a computer security conference. A Program Committee comprising 141 experts from 20 countries, helped by 360 external reviewers, evaluated these submissions, employing the customary double-blind review procedure. The review process had a 16.5% acceptance rate, resulting in 137 papers being accepted to the program, and very broad coverage of the entire security area.
The review process was organized in three phases. In the first review round, at least two preliminary reviews were written for each paper. Most papers went on to a second round, during which at least one additional review was solicited. At this point, the authors were given an opportunity to respond to the comments received (in a rebuttal phase). Finally, in the third round, the program committee actively and comprehensively discussed the papers, and, if necessary, requested additional reviews. Within the program committee, a "rebuttal committee" subgroup helped to spur discussion, to ensure that author responses were considered carefully, and to reflect the post-review discussion in the feedback to authors. New this year, we relied heavily on the TPMS system for assigning submissions to reviews, and we thank Laurent Charlin for writing this system and for all his help with using it.