Quantum cryptography as a retrodiction problem

We propose a quantum key distribution protocol based on a quantum retrodiction protocol, known as the Mean King problem. The protocol uses a two way quantum channel. We show security against coherent attacks in a transmission error free scenario, even if Eve is allowed to attack both transmissions. This establishes a connection between retrodiction and key distribution.Comment: 5 pages, 1 figur

Discovery of an OVI Emitting Nebula around the Hot White Dwarf KPD 0005+5106

A survey of diffuse interstellar sight lines observed with the Far Ultraviolet Spectroscopic Explorer has led to the serendipitous discovery of a high-ionization nebula around the hot white dwarf KPD 0005+5106. The nebula has an OVI 1032A surface brightness of up to 25,000 photons/s/cm^2/sr, making it the brightest region of extended OVI emission in our survey. Photoionization models using the incident white dwarf continuum successfully reproduce the observed OVI intensity. The OVI emission arises in the highly ionized inner region of a planetary nebula around KPD 0005+5106. This newly discovered nebula may be one member of a class of high-ionization planetary nebulae that are difficult to detect in the optical, but which can be easily identified in the ultraviolet.Comment: accepted for publication in ApJL, 11 pages including 2 figure

Good Corporate Governance And Earnings Management Practices: An Indonesian Cases

This research is done for the purpose of finding out the effect of Good Governance practice can reduce earnings management practice done by company. This research uses companies registered in manufacture sector in Indonesia Stock Exchange observation period 2005-2007 as samples. Last sample used in this research is 384 years of observation. This research uses OLS method. The result shows that only two variables have significant effect to Earning Management practice which is CEO Duality and controlling shareholder existence. Other independent variables such as independent commissioner and audit committee and also shareholder coalition outside the controlling shareholder don’t have any effect to earning management practice in the company. Control variable like coverage analyst and debt don’t have any effect either, to earning management practice existence.Keywords: Good Corporate Governance, Earnings Management, Coverage Analyst, Debt