Modeling of f-electron systems is challenging due to the complex interplay of the effects of spin–orbit coupling,electron–electron interactions,and the hybridization of the localized f-electrons with itinerant condu...Modeling of f-electron systems is challenging due to the complex interplay of the effects of spin–orbit coupling,electron–electron interactions,and the hybridization of the localized f-electrons with itinerant conduction electrons.This complexity drives not only the richness of electronic properties but also makes these materials suitable for diverse technological applications.In this context,we propose and implement a data-driven approach to aid the materials discovery process.By deploying state-of-the-art algorithms and query tools,we train our learning models using a large,simulated dataset based on existing actinide and lanthanide compounds.The machine-learned models so obtained can then be used to search for new classes of stable materials with desired electronic and physical properties.We discuss the basic structure of our f-electron database,and our approach towards cleaning and correcting the structure data files.Illustrative examples of the applications of our database include successful prediction of stable superstructures of double perovskites and identification of a number of physically-relevant trends in strongly correlated features of f-electron based materials.展开更多
Asymmetric cryptographic schemes, represe nted by RSA, have bee n show n to be in secure un der quantum computing conditions. Correspondingly, there is a need to study whether the symmetric cryptosystem can still guar...Asymmetric cryptographic schemes, represe nted by RSA, have bee n show n to be in secure un der quantum computing conditions. Correspondingly, there is a need to study whether the symmetric cryptosystem can still guarantee high security with the advent of quantum computers. In this paper, based on the basic principles of classical slide attacks and Simon's algorithm, we take LED-like lightweight block ciphers as research objects to present a security analysis under both classical and quantum attacks, fully considering the influence on the security of the ciphers of adding the round constants. By analyzing the information leakage of round constants, we can introduce the differential of the round constants to propose a classical slide attack on full-round LED-64 with a probability of 1. The analysis result shows that LED-64 is unable to resist this kind of classical slide attack, but that attack method is not applicable to LED-128. As for quantum attacks, by improving on existing quantum attack methods we dem on strate a qua ntum single-key slide attack on LED-64 and a quantum related-key attack on LED- 128, and indicators of the two attack algorithms are analyzed in detail. The attack results show that adding round consta nts does not completely improve the security of the ciphers, and quantum attacks can provide an exp on ential speed-up over the same attacks in the classical model. It further illustrates that the block cipher that is proved to be safe under classical settings is not necessarily secure under quantum conditions.展开更多
基金This work is supported by the Institute for Materials Sciences(IMS),NSEC at LANL and by the U.S.D.O.E at LANL under Project No.20170680ER(T.A.)through the LANL LDRD program.Work at LANL was supported in part by U.S.DOE Basic Energy Sciences Core Program LANL E3B5(J.-X.Z.and A.V.B.)The work at Northeastern University is supported by the US Department of Energy,Office of Science,Basic Energy Sciences grant number DE-FG02-07ER46352benefitted from Northeastern University’s Advanced Scientific Computation Center(ASCC)and the NERSC supercomputing center through DOE grant number DE-AC02-05CH11231.
文摘Modeling of f-electron systems is challenging due to the complex interplay of the effects of spin–orbit coupling,electron–electron interactions,and the hybridization of the localized f-electrons with itinerant conduction electrons.This complexity drives not only the richness of electronic properties but also makes these materials suitable for diverse technological applications.In this context,we propose and implement a data-driven approach to aid the materials discovery process.By deploying state-of-the-art algorithms and query tools,we train our learning models using a large,simulated dataset based on existing actinide and lanthanide compounds.The machine-learned models so obtained can then be used to search for new classes of stable materials with desired electronic and physical properties.We discuss the basic structure of our f-electron database,and our approach towards cleaning and correcting the structure data files.Illustrative examples of the applications of our database include successful prediction of stable superstructures of double perovskites and identification of a number of physically-relevant trends in strongly correlated features of f-electron based materials.
基金supported by the Foundation of Science and Technology on Information Assurance Laboratory(No.KJ-17-003)
文摘Asymmetric cryptographic schemes, represe nted by RSA, have bee n show n to be in secure un der quantum computing conditions. Correspondingly, there is a need to study whether the symmetric cryptosystem can still guarantee high security with the advent of quantum computers. In this paper, based on the basic principles of classical slide attacks and Simon's algorithm, we take LED-like lightweight block ciphers as research objects to present a security analysis under both classical and quantum attacks, fully considering the influence on the security of the ciphers of adding the round constants. By analyzing the information leakage of round constants, we can introduce the differential of the round constants to propose a classical slide attack on full-round LED-64 with a probability of 1. The analysis result shows that LED-64 is unable to resist this kind of classical slide attack, but that attack method is not applicable to LED-128. As for quantum attacks, by improving on existing quantum attack methods we dem on strate a qua ntum single-key slide attack on LED-64 and a quantum related-key attack on LED- 128, and indicators of the two attack algorithms are analyzed in detail. The attack results show that adding round consta nts does not completely improve the security of the ciphers, and quantum attacks can provide an exp on ential speed-up over the same attacks in the classical model. It further illustrates that the block cipher that is proved to be safe under classical settings is not necessarily secure under quantum conditions.