@misc{cryptoeprint:2011:406,
author = {Ralf Kuesters and Max Tuengerthal},
title = {Composition Theorems Without Pre-Established Session Identifiers},
howpublished = {Cryptology ePrint Archive, Report 2011/406},
year = {2011},
note = {\url{http://eprint.iacr.org/}},
}
You will need the url.sty package (comes with most LaTeX installations) for the last line. Otherwise, remove the \url command.