X-ray and radio prompt emission from a hypernova SN 2002ap

Here we report on combined X-ray and radio observations of SN 2002ap with XMM-Newton ToO observation and GMRT observations aided with VLA published results. In deriving the X-ray flux of SN 2002ap we account for the contribution of a nearby source, found to be present in the pre-SN explosion images obtained with Chandra observatory. We also derive upper limits on mass loss rate from X-ray and radio data. We suggest that the prompt X-ray emission is non-thermal in nature and its is due to the repeated compton boosting of optical photons. We also compare SN's early radiospheric properties with two other SNe at the same epoch.Comment: 4 pages, 5 figures. Uses espcrc2.sty. To appear in proceedings of symposium on X-ray astronomy "The Restless High-Energy Universe", May 2003, Amsterdam, The Netherlands, eds. E.P.J. van den Heuvel, J.J.M. in 't Zand, and R.A.M.J. Wijer

Mitigating Branch-Shadowing Attacks on Intel SGX using Control Flow Randomization

Intel Software Guard Extensions (SGX) is a promising hardware-based technology for protecting sensitive computations from potentially compromised system software. However, recent research has shown that SGX is vulnerable to branch-shadowing -- a side channel attack that leaks the fine-grained (branch granularity) control flow of an enclave (SGX protected code), potentially revealing sensitive data to the attacker. The previously-proposed defense mechanism, called Zigzagger, attempted to hide the control flow, but has been shown to be ineffective if the attacker can single-step through the enclave using the recent SGX-Step framework. Taking into account these stronger attacker capabilities, we propose a new defense against branch-shadowing, based on control flow randomization. Our scheme is inspired by Zigzagger, but provides quantifiable security guarantees with respect to a tunable security parameter. Specifically, we eliminate conditional branches and hide the targets of unconditional branches using a combination of compile-time modifications and run-time code randomization. We evaluated the performance of our approach by measuring the run-time overhead of ten benchmark programs of SGX-Nbench in SGX environment

Hot QCD equations of state and RHIC

We show how hot QCD equations of states can be adapted to make definite predictions for quark-gluon plasma at RHIC. We consider equations of state up to $O(g^5)$ and $O[g^6(ln(1/g)+\delta)]$. Our method involves the extraction of equilibrium distribution functions for gluons and quarks from these equations of state by capturing the the interaction effects entirely in the effective chemical potentials. We further utilize these distribution functions to study the screening length in hot QCD and dissociation phenomenon of heavy quarkonia states by combining this understanding with the semi-classical transport theory.Comment: Based on poster presented during quark matter-2008(4-10 Feb 2008) Jaipur India; 4 Pages, 2 eps fig