Proceedings of the 18th ACM Conference on Computer and Communications Security, CCS 2011, Chicago, Illinois, USA, October 17-21, 2011

It is a pleasure to present to you the proceedings of this year's ACM Conference on Computer and Communications Security (CCS 2011), held October 17-21 in Chicago, Illnois, USA. This year we received a record 429 submissions from 39 countries. Each submission was reviewed by the technical program committee of 53 experts, as well as over 280 external reviewers. The final program contains 60 full papers, representing the acceptance rate of 14%. The single-blind review process was organised in two rounds spanning 10 weeks. It included an opportunity for the authors to respond to reviews after the first round. Author response was followed by an electronic discussion among the PC members. Many reviews were assigned to PC members dynamically to maximise scrutiny and discussion of the submissions whose inclusion in the program was most uncertain. Overall, 1366 reviews were filed, including 430 from external reviewers. Despite the unexpected increase in submissions relative to CCS 2010, 327 papers received at least 3 reviews and 158 papers received at least 4 reviews, with some receiving as many as 5 or 6 reviews. The decision to allocate fewer than 3 reviews to some papers was taken on the basis of both the qualitative feedback from the first-round reviewers and a systematic quantitative analysis of the likelihood of their acceptance given the first-round reviews. Many papers that could not be selected for presentation contained interesting results and ideas. We hope that the reviews will help improve these papers for future re-submissions. We also worked closely with the program chairs of CCS-affiliated workshops to ensure that the authors of rejected papers had an opportunity to submit their work to those venues.