Abstract: We introduce the notion of \emph{universal parameters} as a method for generating the trusted parameters for many schemes from just a single trusted setup. In such a scheme a trusted setup process will produce universal parameters $U$. These parameters can then be combined with the description, $d(\cdot)$ of any particular cryptographic setup algorithm to produce parameters $p_d$ that can be used by the cryptographic system associated with $d$. We give a solution in the random oracle model based on indistinguishability obfuscation.
more here..............http://eprint.iacr.org/2014/507.pdf
more here..............http://eprint.iacr.org/2014/507.pdf