Digital signature is one of the most important cryptographic primitives. We proposed a new digital signature scheme based on Catalano’s trapdoor. Since Catalano’s trapdoor is more efficient than existing trapdoors i...Digital signature is one of the most important cryptographic primitives. We proposed a new digital signature scheme based on Catalano’s trapdoor. Since Catalano’s trapdoor is more efficient than existing trapdoors in number theory, our scheme need not modular exponentiation but several modular multiplications in the signing algorithm. We also proved our scheme is provably secure against adap-tively chosen message attack by using the Forking lemma.展开更多
A new collapse model of the trapdoors,three-dimensional rectangular trapdoor(3DRT),is presented for ground surface collapse.Undrained stability of 3DRT is examined with the upper bound method of plasticity limit analy...A new collapse model of the trapdoors,three-dimensional rectangular trapdoor(3DRT),is presented for ground surface collapse.Undrained stability of 3DRT is examined with the upper bound method of plasticity limit analysis theory.The soil where the trapdoors are located is assumed to be a perfectly plastic model with a Tresca yield criterion.Block analysis technique is employed to investigate the collapse of 3DRT.The model is divided into five different block types and added up to ten rigid blocks.According to the law of conservation of energy,the critical stability ratios of 3DRT are obtained through a search proceeding.The results of upper bound solution for 3DRT are given,and three trapdoor models with depth various are discussed during the application in the stability analysis of square trapdoors.The critical stability ratios can be used in the design of underground excavation and support force.展开更多
Chameleon all-but-one trapdoor functions(ABO-TDFs) were introduced by Lai et al. An important component of the existing constructions of chameleon ABO-TDFs based on the decisional Diffie-Hellman(DDH)assumption was the...Chameleon all-but-one trapdoor functions(ABO-TDFs) were introduced by Lai et al. An important component of the existing constructions of chameleon ABO-TDFs based on the decisional Diffie-Hellman(DDH)assumption was the chameleon hash functions. In this paper, we instantiate the first chameleon ABO-TDFs based on DDH free of chameleon hash functions.展开更多
Trapdoor stability has been widely studied by many researchers in the field of tunneling engineering.A general question being fre-quently asked is that why most sinkholes have a near-perfect circular shape on the grou...Trapdoor stability has been widely studied by many researchers in the field of tunneling engineering.A general question being fre-quently asked is that why most sinkholes have a near-perfect circular shape on the ground surface.This could be possibly explained by the current numerical study using finite element limit analysis under axisymmetric condition,where upper and lower bound solutions of active circular trapdoors are determined.The failure study of sinkholes and the associated failure mechanisms in this paper are for non-homogeneous clay with a linear increase of strength with depth under various cover depth ratios and dimensionless strength gra-dients.A design equation for predicting the stability solutions is also developed based on the novel three dimensional solutions using axisymmetry.展开更多
基金Supported by the National Natural Science Foundation of China (No. 60703086)Program for Excellent Talents in Nanjing University of Posts and Telecommunications(No. NY209014)
文摘Digital signature is one of the most important cryptographic primitives. We proposed a new digital signature scheme based on Catalano’s trapdoor. Since Catalano’s trapdoor is more efficient than existing trapdoors in number theory, our scheme need not modular exponentiation but several modular multiplications in the signing algorithm. We also proved our scheme is provably secure against adap-tively chosen message attack by using the Forking lemma.
基金the Fundamental Research Funds for the Provincial Universities,China(No.702/000007020303)。
文摘A new collapse model of the trapdoors,three-dimensional rectangular trapdoor(3DRT),is presented for ground surface collapse.Undrained stability of 3DRT is examined with the upper bound method of plasticity limit analysis theory.The soil where the trapdoors are located is assumed to be a perfectly plastic model with a Tresca yield criterion.Block analysis technique is employed to investigate the collapse of 3DRT.The model is divided into five different block types and added up to ten rigid blocks.According to the law of conservation of energy,the critical stability ratios of 3DRT are obtained through a search proceeding.The results of upper bound solution for 3DRT are given,and three trapdoor models with depth various are discussed during the application in the stability analysis of square trapdoors.The critical stability ratios can be used in the design of underground excavation and support force.
基金the National Natural Science Foundation of China(Nos.61373153 and 61170229)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20110073110016)the Scientific Innovation Projects of Shanghai Municipal Education Committee(No.12ZZ021)
文摘Chameleon all-but-one trapdoor functions(ABO-TDFs) were introduced by Lai et al. An important component of the existing constructions of chameleon ABO-TDFs based on the decisional Diffie-Hellman(DDH)assumption was the chameleon hash functions. In this paper, we instantiate the first chameleon ABO-TDFs based on DDH free of chameleon hash functions.
文摘Trapdoor stability has been widely studied by many researchers in the field of tunneling engineering.A general question being fre-quently asked is that why most sinkholes have a near-perfect circular shape on the ground surface.This could be possibly explained by the current numerical study using finite element limit analysis under axisymmetric condition,where upper and lower bound solutions of active circular trapdoors are determined.The failure study of sinkholes and the associated failure mechanisms in this paper are for non-homogeneous clay with a linear increase of strength with depth under various cover depth ratios and dimensionless strength gra-dients.A design equation for predicting the stability solutions is also developed based on the novel three dimensional solutions using axisymmetry.
