Public key cryptographic （PKC） algorithms, such as the RSA, elliptic curve digital signature algorithm （ECDSA） etc., are widely used in the secure communication sys- tems, such as OpenSSL, and a variety of in- for...Public key cryptographic （PKC） algorithms, such as the RSA, elliptic curve digital signature algorithm （ECDSA） etc., are widely used in the secure communication sys- tems, such as OpenSSL, and a variety of in- formation security systems. If designer do not securely implement them, the secret key will be easily extracted by side-channel attacks （SCAs） or combinational SCA thus mitigat- ing the security of the entire communication system. Previous countermeasures of PKC im- plementations focused on the core part of the algorithms and ignored the modular inversion which is widely used in various PKC schemes. Many researchers believe that instead of straightforward implementation, constant time modular inversion （CTMI） is enough to resist the attack of simple power analysis combined with lattice analysis. However, we find that the CTMI security can be reduced to a hidden t-bit multiplier problem. Based on this feature, we firstly obtain Hamming weight of interme- diate data through side-channel leakage. Then, we propose a heuristic algorithm to solve the problem by revealing the secret （partial and full） base of CTMI. Comparing previous nec-essary input message for masking filtering, our procedure need not any information about the secret base of the inversion. To our knowl- edge, this is the first time for evaluating the practical security of CTM! and experimental results show the fact that CTMI is not enough for high-level secure communication systems.展开更多
The development of smart windows based on electrochromic technology offers a promising route to reduce building energy consumption.However,conventional magnetron-sputtered inorganic electrochromic films,though robust ...The development of smart windows based on electrochromic technology offers a promising route to reduce building energy consumption.However,conventional magnetron-sputtered inorganic electrochromic films,though robust and industrially compatible,suffer from intrinsically sluggish ion transport and limited optical modulation due to their compact morphology,a long-standing bottleneck restricting their practical performance.Here,we report a lunar craterinspired nanostructuring strategy that creates vertically aligned and depth-tunable crater arrays within amorphous magnetron-sputtered electrochromic films without compromising their mechanical and structural integrity.These craters extend through the full thickness of the film to the underlying conductive electrode,establishing continuous three-dimensional(3D)lateral pathways for rapid ion diffusion.Using tungsten oxide(WO3)as a representative model,the resulted crater-like nanostructured WO3 films present markedly enhanced electrochromic performance,significantly surpassing previously reported values for sputtered inorganic films.Notably,the progressive ions efficiently insert into entire WO3 films along the 3D lateral to complete a full coloring switch and obtain a superior transmittance of only 2.23%.Additionally,the shortened ion transport pathways enabled by the 3D lateral diffusion in synergy with vertical injection largely accelerate the ion diffusion and migration processes,boasting a rapid switching time and a remarkable optical modulation exceeding 89.19%coloring in just 5.4 s.This work overcomes the fundamental trade-off between switching speed and optical contrast in conventional dense electrochromic layers and provides a universal platform for designing high-performance ion-involved solid-state devices through nanostructural engineering.展开更多
基金supported by the Key Technology Research and Sample-Chip Manufacture on Resistance to Physical Attacks at Circuit Level(546816170002)
文摘Public key cryptographic （PKC） algorithms, such as the RSA, elliptic curve digital signature algorithm （ECDSA） etc., are widely used in the secure communication sys- tems, such as OpenSSL, and a variety of in- formation security systems. If designer do not securely implement them, the secret key will be easily extracted by side-channel attacks （SCAs） or combinational SCA thus mitigat- ing the security of the entire communication system. Previous countermeasures of PKC im- plementations focused on the core part of the algorithms and ignored the modular inversion which is widely used in various PKC schemes. Many researchers believe that instead of straightforward implementation, constant time modular inversion （CTMI） is enough to resist the attack of simple power analysis combined with lattice analysis. However, we find that the CTMI security can be reduced to a hidden t-bit multiplier problem. Based on this feature, we firstly obtain Hamming weight of interme- diate data through side-channel leakage. Then, we propose a heuristic algorithm to solve the problem by revealing the secret （partial and full） base of CTMI. Comparing previous nec-essary input message for masking filtering, our procedure need not any information about the secret base of the inversion. To our knowl- edge, this is the first time for evaluating the practical security of CTM! and experimental results show the fact that CTMI is not enough for high-level secure communication systems.
基金support from the National Key Research and Development Program of China(No.2024YFB3614500)the Natural Science Foundation of Xiamen City(Nos.3502Z20227063 and 3502Z202372049)+2 种基金the National Natural Science Foundation of China(Nos.62304189,52373194,and 52403301)the Natural Science Foundation of Fujian Province(Nos.2023J011450 and 2024J011211)the Guang Dong Basic and Applied Basic Research Foundation(No.2022A1515110727).
文摘The development of smart windows based on electrochromic technology offers a promising route to reduce building energy consumption.However,conventional magnetron-sputtered inorganic electrochromic films,though robust and industrially compatible,suffer from intrinsically sluggish ion transport and limited optical modulation due to their compact morphology,a long-standing bottleneck restricting their practical performance.Here,we report a lunar craterinspired nanostructuring strategy that creates vertically aligned and depth-tunable crater arrays within amorphous magnetron-sputtered electrochromic films without compromising their mechanical and structural integrity.These craters extend through the full thickness of the film to the underlying conductive electrode,establishing continuous three-dimensional(3D)lateral pathways for rapid ion diffusion.Using tungsten oxide(WO3)as a representative model,the resulted crater-like nanostructured WO3 films present markedly enhanced electrochromic performance,significantly surpassing previously reported values for sputtered inorganic films.Notably,the progressive ions efficiently insert into entire WO3 films along the 3D lateral to complete a full coloring switch and obtain a superior transmittance of only 2.23%.Additionally,the shortened ion transport pathways enabled by the 3D lateral diffusion in synergy with vertical injection largely accelerate the ion diffusion and migration processes,boasting a rapid switching time and a remarkable optical modulation exceeding 89.19%coloring in just 5.4 s.This work overcomes the fundamental trade-off between switching speed and optical contrast in conventional dense electrochromic layers and provides a universal platform for designing high-performance ion-involved solid-state devices through nanostructural engineering.
