This book constitutes the refereed proceedings of the 16th European Symposium on Computer Security, ESORICS 2011, held in Leuven, Belgium, in September 2011. The 36 papers included in the book were carefully reviewed and selected from 155 papers. The articles are organized in topical sections on wireless security; Web security; forensics, biometrics and software protection; access control; cryptography and protocol analysis; information flow, side channels, and vulnerability analysis; usability, trust, and economics of security and privacy; and privacy.