Experimental study of quantum random number generator based on two independent lasers

Quantum random number generator (QRNG) can produce true randomness by utilizing the inherent probabilistic nature of quantum mechanics. Recently, the spontaneous-emission quantum phase noise of the laser has been widely deployed for QRNG, due to its high rate, low cost and the feasibility of chip-scale integration. Here, we perform a comprehensive experimental study of phase-noise based QRNG with two independent lasers, each of which operates in either continuous-wave (CW) or pulsed mode. We implement QRNGs by operating the two lasers in three configurations, namely CW+CW, CW+pulsed and pulsed+pulsed, and demonstrate their tradeoffs, strengths and weaknesses.Comment: 7pages,6figures.It has been accepted by PR

4-{4-Methyl-2-[(meth­yl)(2-methyl­phen­yl)amino]-1,3-thia­zol-5-yl}-N-(3-methyl­phen­yl)pyrimidin-2-amine

In the title compound, C23H23N5S, the thia­zole ring and pyrimidine ring are almost coplanar, making a dihedral angle of 4.02 (9)°. in the crystal, weak inter­molecular N—H⋯N inter­actions link pairs of molecules into centrosymmetric dimers

Effect of source tampering in the security of quantum cryptography

The security of source has become an increasingly important issue in quantum cryptography. Based on the framework of measurement-device-independent quantum-key-distribution (MDI-QKD), the source becomes the only region exploitable by a potential eavesdropper (Eve). Phase randomization is a cornerstone assumption in most discrete-variable (DV-) quantum communication protocols (e.g., QKD, quantum coin tossing, weak coherent state blind quantum computing, and so on), and the violation of such an assumption is thus fatal to the security of those protocols. In this paper, we show a simple quantum hacking strategy, with commercial and homemade pulsed lasers, by Eve that allows her to actively tamper with the source and violate such an assumption, without leaving a trace afterwards. Furthermore, our attack may also be valid for continuous-variable (CV-) QKD, which is another main class of QKD protocol, since, excepting the phase random assumption, other parameters (e.g., intensity) could also be changed, which directly determine the security of CV-QKD.Comment: 9 pages, 6 figure