A new algorithm for a novel hash function, based on chaotic tent map with changeable parameter, is proposed and analyzed. The one dimensional and piecewise tent map with changeable parameters decided by the position i...A new algorithm for a novel hash function, based on chaotic tent map with changeable parameter, is proposed and analyzed. The one dimensional and piecewise tent map with changeable parameters decided by the position index of blocked messages is chosen, and blocked massages translated into ASCII code values are employed as the iteration time of the chaotic tent map. The final 128-bit hash value is generated by logical XOR operation on intermediate hash values. Theoretical analysis and computer simulation indicate that the proposed algorithm can satisfy the performance requirements of hash function.展开更多
We propose the generation of photonic EPR state from quadratic waveguide array. Both the propagation constant and the nonlinearity in the array are designed to possess a periodical modulation along the propagation dir...We propose the generation of photonic EPR state from quadratic waveguide array. Both the propagation constant and the nonlinearity in the array are designed to possess a periodical modulation along the propagation direction.This ensures that the photon pairs can be generated efficiently through the quasi-phase-matching spontaneous parametric down conversion by holding the spatial EPR entanglement in the fashion of correlated position and anticorrelated momentum. The Schmidt number which denotes the degree of EPR entanglement is calculated and it can approach a high value when the number of illuminated waveguide channels and the length of the waveguide array are properly chosen. These results suggest the quadratic waveguide array as a compact platform for engineering photonic quantum states in a high-dimensional Hilbert space.展开更多
基金Supported by the National Natural Science Foundation of China （No. 61173178, 61003247, 61070246） and the Fundamental Research Funds for the Central University （No. COJER1018002,cdjerl018003）.
文摘A new algorithm for a novel hash function, based on chaotic tent map with changeable parameter, is proposed and analyzed. The one dimensional and piecewise tent map with changeable parameters decided by the position index of blocked messages is chosen, and blocked massages translated into ASCII code values are employed as the iteration time of the chaotic tent map. The final 128-bit hash value is generated by logical XOR operation on intermediate hash values. Theoretical analysis and computer simulation indicate that the proposed algorithm can satisfy the performance requirements of hash function.
基金Supported by the State Key Program for Basic Research in China under Grant No.2012CB921802 the National Natural Science Foundations of China under Grant Nos.91321312,11321063 and 11422438
文摘We propose the generation of photonic EPR state from quadratic waveguide array. Both the propagation constant and the nonlinearity in the array are designed to possess a periodical modulation along the propagation direction.This ensures that the photon pairs can be generated efficiently through the quasi-phase-matching spontaneous parametric down conversion by holding the spatial EPR entanglement in the fashion of correlated position and anticorrelated momentum. The Schmidt number which denotes the degree of EPR entanglement is calculated and it can approach a high value when the number of illuminated waveguide channels and the length of the waveguide array are properly chosen. These results suggest the quadratic waveguide array as a compact platform for engineering photonic quantum states in a high-dimensional Hilbert space.
