@TechReport{ sprenger.ea:refining:2011, author = {Christoph Sprenger and David Basin}, institution = {Computer Science Department, ETH Zurich}, language = {USenglish}, month = {Sep}, number = 736, title = {Refining Key Establishment}, url = {ftp://ftp.inf.ethz.ch/pub/publications/tech-reports/7xx/736.pdf} , year = 2011, user = {csprenge} }