In ASIACCS 2015, Nu nez, et al. proposed a proxy re-encryption scheme, named NTRURe Encrypt, based on NTRU, which allows a proxy to translate ciphertext under the delegator’s public key into a re-encrypted ciphertext...In ASIACCS 2015, Nu nez, et al. proposed a proxy re-encryption scheme, named NTRURe Encrypt, based on NTRU, which allows a proxy to translate ciphertext under the delegator’s public key into a re-encrypted ciphertext that can be decrypted correctly by delegatee’s private key. Because of the potential resistance to quantum algorithm, high efficiency and various applications in real life,NTRURe Encrypt has drawn lots of attention and its security has been widely discussed and analyzed.In PQCrypto2019, Liu, et al. proposed two key recovery attacks against it. However, their first attack heavily relies on a weaken decryption oracle, and the second attack needs to collect about 260ciphertexts from the same message by theoretical analysis, which makes both of the attacks unrealistic. In this paper, inspired by the broadcast attack against NTRU, the authors find out that for NTRURe Encrypt the delegator and the delegatee can efficiently recover each other’s private key in polynomial time without any unrealistic assumptions. In addition, the authors also show how to fix NTRURe Encrypt to resist the proposed attacks. As a by-product, the authors also show how to commit broadcast attacks against NTRU 2001 with even dg, which was thought infeasible before.展开更多
Soil carbon stocks and sequestration have been given a lot of attention recently in the study of terrestrial ecosystems and global climate change.This review focuses on the progress made on the estimation of the soil ...Soil carbon stocks and sequestration have been given a lot of attention recently in the study of terrestrial ecosystems and global climate change.This review focuses on the progress made on the estimation of the soil carbon stocks of China,and the characterization of carbon dynamics of croplands with regard to climate change,and addresses issues on the mineralization of soil organic carbon in relation to greenhouse gas emissions.By integrating existing research data,China's total soil organic carbon(SOC) stock is estimated to be 90 Pg and its inorganic carbon(SIC) stock as 60 Pg,with SOC sequestration rates in the range of 20-25 Tg/a for the last two decades.An estimation of the biophysical potential of SOC sequestration has been generally agreed as being 2 Pg over the long term,of which only 1/3 could be attainable using contemporary agricultural technologies in all of China's croplands.Thus,it is critical to enhance SOC sequestration and mitigate climate change to improve agricultural and land use management in China.There have been many instances where SOC accumulation may not induce an increased amount of decomposition under a warming scenario but instead favor improved cropland productivity and ecosystem functioning.Furthermore,unchanged or even decreased net global warming potential(GWP) from croplands with enhanced SOC has been reported by a number of case studies using life cycle analysis.Future studies on soil carbon stocks and the sequestration potential of China are expected to focus on:(1) Carbon stocks and the sequestration capacity of the earths' surface systems at scales ranging from the plot to the watershed and(2) multiple interface processes and the synergies between carbon sequestration and ecosystem productivity and ecosystem functioning at scales from the molecular level to agro-ecosystems.Soil carbon science in China faces new challenges and opportunities to undertake integrated research applicable to many areas.展开更多
基金supported by National Key Research and Development Program of China under Grant No.2018YFA0704705the National Natural Science Foundation of China under Grant Nos. 62032009, 12201193+3 种基金12226006the Innovation Program for Quantum Science and Technology under Grant No. 2021ZD0302902the Innovation Group Project of the Natural Science Foundation of Hubei Province of China under Grant No.2023AFA021the Science and Technology Research Program of Education Department of Hubei Province under Grant No. Q20221008。
文摘In ASIACCS 2015, Nu nez, et al. proposed a proxy re-encryption scheme, named NTRURe Encrypt, based on NTRU, which allows a proxy to translate ciphertext under the delegator’s public key into a re-encrypted ciphertext that can be decrypted correctly by delegatee’s private key. Because of the potential resistance to quantum algorithm, high efficiency and various applications in real life,NTRURe Encrypt has drawn lots of attention and its security has been widely discussed and analyzed.In PQCrypto2019, Liu, et al. proposed two key recovery attacks against it. However, their first attack heavily relies on a weaken decryption oracle, and the second attack needs to collect about 260ciphertexts from the same message by theoretical analysis, which makes both of the attacks unrealistic. In this paper, inspired by the broadcast attack against NTRU, the authors find out that for NTRURe Encrypt the delegator and the delegatee can efficiently recover each other’s private key in polynomial time without any unrealistic assumptions. In addition, the authors also show how to fix NTRURe Encrypt to resist the proposed attacks. As a by-product, the authors also show how to commit broadcast attacks against NTRU 2001 with even dg, which was thought infeasible before.
基金supported by the National Natural Science Foundation of China (40830528 and 40270010092)supported by travel funds from a UK BBSRC China Partnership Award. PS is a Royal Society-Wolfson Research Merit Award holder
文摘Soil carbon stocks and sequestration have been given a lot of attention recently in the study of terrestrial ecosystems and global climate change.This review focuses on the progress made on the estimation of the soil carbon stocks of China,and the characterization of carbon dynamics of croplands with regard to climate change,and addresses issues on the mineralization of soil organic carbon in relation to greenhouse gas emissions.By integrating existing research data,China's total soil organic carbon(SOC) stock is estimated to be 90 Pg and its inorganic carbon(SIC) stock as 60 Pg,with SOC sequestration rates in the range of 20-25 Tg/a for the last two decades.An estimation of the biophysical potential of SOC sequestration has been generally agreed as being 2 Pg over the long term,of which only 1/3 could be attainable using contemporary agricultural technologies in all of China's croplands.Thus,it is critical to enhance SOC sequestration and mitigate climate change to improve agricultural and land use management in China.There have been many instances where SOC accumulation may not induce an increased amount of decomposition under a warming scenario but instead favor improved cropland productivity and ecosystem functioning.Furthermore,unchanged or even decreased net global warming potential(GWP) from croplands with enhanced SOC has been reported by a number of case studies using life cycle analysis.Future studies on soil carbon stocks and the sequestration potential of China are expected to focus on:(1) Carbon stocks and the sequestration capacity of the earths' surface systems at scales ranging from the plot to the watershed and(2) multiple interface processes and the synergies between carbon sequestration and ecosystem productivity and ecosystem functioning at scales from the molecular level to agro-ecosystems.Soil carbon science in China faces new challenges and opportunities to undertake integrated research applicable to many areas.
