Side Channels of Information Leakage in Quantum Cryptography: Nonstrictly Single-Photon States,Different Quantum Efficiencies of Detectors,and Finite Transmitted Sequences

Journal of Experimental and Theoretical Physics - The implementation of quantum cryptography systems significantly differs from idealized models used to prove the secrecy of distributed keys....     

Trimethylammonium-containing rhodacarborane [(9-NMe3-7,8-C2B9H10)RhCl2]2 as a catalyst for the annulation of arylcarboxylic acids with alkynes

Russian Chemical Bulletin - Rhodacarborane [(9-NMe3-7,8-C2B9H10)RhCl2]2 exhibited moderate catalytic activity in the reaction of annulation of arylcarboxylic acids with alkynes, giving naphthalenes...     

Kinetic Theory of Boson Gas

Theoretical and Mathematical Physics - We construct a quantum kinetic theory of a weakly interacting critical boson gas using the expectation values of products of Heisenberg field operators in the...     

Predicting the deformation characteristics of polymer materials

Theoretical methods of predicting the deformation characteristics of polymers are considered. The principles of reduced variables are examined. The relation between characteristics functions of polymers is analyzed. A prediction method is considered for polymers; the method is based upon the use of macroscopical mechanical models having a basis in terms of physics.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 2, pp. 147–152, March–April, 1973.     

Quantum Key Distribution with Untrusted Detectors Accessible to an Eavesdropper

JETP Letters - A simple fundamental modification of quantum key distribution protocols has been proposed: it is not required to protect the results of avalanche detectors from an eavesdropper, but...     

On the vulnerability of the swiss system of coherent quantum cryptography to an attack with repeated measurements

It has been shown that the coherent quantum cryptography protocol (Coherent One Way) and, correspondingly, fiber optic systems involving this protocol for quantum key distribution, are vulnerable to an attack with repeated measurements and do not guarantee the security of distributed keys in a communication channel with losses. The coherent quantum cryptography system is used in Switzerland as one of the key distribution channels in the framework of the network project SECOQC (SEcure COmmunications based on Quantum Cryptography). A critical attack with repeated measurements was missed when the cryptographic strength of this protocol was analyzed. The critical length of the communication channel has been determined; this is a value above which secure key distribution is certainly impossible. Beginning with the critical length, an eavesdropper knows the entire distributed key, does not introduce errors at the receiver end, and remains undetected. For typical parameters in a real system (the average photon number μ = 0.5 and the quantum efficiency of avalanche detectors η = 0.1, see N. Gisin, G. Ribordy, H. Zbinden, et al., arXiv:quant-ph/0411022 and D. Stucki, C. Barreiro, S. Fasel, et al., arXiv:quant-ph/08095264), the security of keys cannot be guaranteed even for a communication channel whose length is as small as wished.     

Critical Dynamics of the Phase Transition to the Superfluid State

Theoretical and Mathematical Physics - In papers devoted to superfluidity, the generally accepted statement that the dynamics of the corresponding phase transition is described by the stochastic...     

Single-phase and multiphase effective models describing periodic media

In this work wave propagation processes are investigated in media obtained by averaging periodic layered systems with fluid, elastic-fluid, and elastic with contact-slippage conditions on the boundaries.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 140, pp. 105–122, 1984.     

Quantum bit commitment in a channel with noise

Under rather general assumptions about the properties of a quantum channel with noise, a quantum protocol providing implementation of secret bit commitment with the probability as close to unity as is wished is proposed.