The quantization of a massless conformally coupled scalar field on the 2+1 dimensional Anti de Sitter black hole background is presented. The Green’s function is calculated, using the fact that the black hole is Anti de Sitter space with points identified, and taking into account the fact that the black hole spacetime is not globally hyperbolic. It is shown that the Green’s function calculated ...

‎a $mu$-way $(v,k,t)$ $trade$ of volume $m$ consists of $mu$‎ ‎disjoint collections $t_1$‎, ‎$t_2‎, ‎dots t_{mu}$‎, ‎each of $m$‎ ‎blocks‎, ‎such that for every $t$-subset of $v$-set $v$ the number of‎ ‎blocks containing this t-subset is the same in each $t_i (1leq‎ ‎i leq mu)$‎. ‎in other words any pair of collections ${t_i,t_j}$‎, ‎$1leq i< j leq mu‎$ is a $(v,k,t)$ trade of volume $m$. in th...

We describe a new version of the elliptic curve encryption schemes PSEC (Provably Secure Elliptic Curve). PSEC{3 is a public-key encryption system that uses the elliptic curve El Gamal trapdoor function and two random functions (hash functions) as well as any semantically secure symmetric encryption scheme, such as the one-time pad, or any classical block-cipher. Furthermore, we de ne a new pro...