Many evidences have showed that some intelligence agencies(often called big brother)attempt to monitor citizens’communication by providing coerced citizens a lot of subverted cryptographic algorithms and coercing the...Many evidences have showed that some intelligence agencies(often called big brother)attempt to monitor citizens’communication by providing coerced citizens a lot of subverted cryptographic algorithms and coercing them to adopt these algorithms.Since legalized services on large number of various applications and system architectures depend on digital signature techniques,in the context some coerced users who use double authentication preventing signatures to design some novel digital signature techniques,have some convincing dissertations to defuse requests from authorities and big brothers creating some corresponding subverted signatures.As rapid progress in quantum computers,National Security Agency advisory memorandum and announcement of National Institute of Standards and Technology procedures from standardization focus on some cryptographic algorithms which are post quantum secure.Motivated by these issues,we design an algorithm substitution attack against Fiat-Shamir family based on lattices(e.g.,BLISS,BG,Ring-TESLA,PASSSign and GLP)that are proven post-quantum computational secure.We also show an efficient deterable way to eliminate big brother’s threat by leaking signing keys from signatures on two messages to be public.Security proof shows that our schemes satisfy key extraction,undetectability and deterability.Through parameters analysis and performance evaluation,we demonstrate that our deterring subverted Fiat-Shamir signature is practical,which means that it can be applied to privacy and protection in some system architectures.展开更多
As a special kind of digital signature, verifiably encrypted signatures are used as a building block to construct optimistic fair exchange. Many verifiably encrypted signature schemes have been proposed so far and mos...As a special kind of digital signature, verifiably encrypted signatures are used as a building block to construct optimistic fair exchange. Many verifiably encrypted signature schemes have been proposed so far and most of them were proven secure under certain complexity assumptions. In this paper, however, we find that although some schemes are secure in a single-user setting, they are not secure in a multi-user setting any more. We show that Zhang, et al. ' s scheme, Gorantla, et al. ' s scheme and Ming, et al. ' s scheme are vulnerable to key substitution attacks, where an adversary can generate new keys satisfying legitimate verifiably encrypted signatures created by the legitimate users. We also show that this kind of attacks can breach the fairness when they are used in fair exchange in a multi-user setting.展开更多
3-Methylthio-5-hydroxy-1,2,4-triazine(1c)reacted with substituted benzenesulfonyl chloride to give 3-methylthio-5-oxy-1,2,4-triazin-6-yl pyridinium betaine(4)in anhydrous pyridine.But when NaOH/H_2O/CH_3COCH_3 or NaOH...3-Methylthio-5-hydroxy-1,2,4-triazine(1c)reacted with substituted benzenesulfonyl chloride to give 3-methylthio-5-oxy-1,2,4-triazin-6-yl pyridinium betaine(4)in anhydrous pyridine.But when NaOH/H_2O/CH_3COCH_3 or NaOH/CH_3OH were used as reactant and solvent,3-methylthio-4-substituted benzenesulfonyl-5-oxo-6-hydroxy-1,4,5,6-tetrahydro-1,2,4-triazine(6)or 1-tosyl-3-methylthio-5-oxo-6-methyloxy-1,4,5,6-tetrahydro-1,2,4-triazine(7)was obtained respectively.The above reactions show anomalous properties of nucleophilic attack on 6-carbon in 1,2,4-triazine ring.展开更多
基金Supported by the National Natural Science Foundation of China(61802239,61872229,62062019,62074131)Key Research and Development Program of Shaanxi Province(2020ZDLGY09-06,2021ZDLGY06-04,2021ZDLGY05-01)+1 种基金Natural Science Basic Research Plan in Shaanxi Province(2019JQ-667,2020JQ-422)Shenzhen Fundamental Research Program(20210317191843003)
文摘Many evidences have showed that some intelligence agencies(often called big brother)attempt to monitor citizens’communication by providing coerced citizens a lot of subverted cryptographic algorithms and coercing them to adopt these algorithms.Since legalized services on large number of various applications and system architectures depend on digital signature techniques,in the context some coerced users who use double authentication preventing signatures to design some novel digital signature techniques,have some convincing dissertations to defuse requests from authorities and big brothers creating some corresponding subverted signatures.As rapid progress in quantum computers,National Security Agency advisory memorandum and announcement of National Institute of Standards and Technology procedures from standardization focus on some cryptographic algorithms which are post quantum secure.Motivated by these issues,we design an algorithm substitution attack against Fiat-Shamir family based on lattices(e.g.,BLISS,BG,Ring-TESLA,PASSSign and GLP)that are proven post-quantum computational secure.We also show an efficient deterable way to eliminate big brother’s threat by leaking signing keys from signatures on two messages to be public.Security proof shows that our schemes satisfy key extraction,undetectability and deterability.Through parameters analysis and performance evaluation,we demonstrate that our deterring subverted Fiat-Shamir signature is practical,which means that it can be applied to privacy and protection in some system architectures.
基金Supported by the National High Technology Research and Development Programme of China ( No. 2008AA092301 ) and the National Natural Science Foundation of China (No. 50879014).
文摘As a special kind of digital signature, verifiably encrypted signatures are used as a building block to construct optimistic fair exchange. Many verifiably encrypted signature schemes have been proposed so far and most of them were proven secure under certain complexity assumptions. In this paper, however, we find that although some schemes are secure in a single-user setting, they are not secure in a multi-user setting any more. We show that Zhang, et al. ' s scheme, Gorantla, et al. ' s scheme and Ming, et al. ' s scheme are vulnerable to key substitution attacks, where an adversary can generate new keys satisfying legitimate verifiably encrypted signatures created by the legitimate users. We also show that this kind of attacks can breach the fairness when they are used in fair exchange in a multi-user setting.
基金Director of the project supported by National Natural Science foundation of China.
文摘3-Methylthio-5-hydroxy-1,2,4-triazine(1c)reacted with substituted benzenesulfonyl chloride to give 3-methylthio-5-oxy-1,2,4-triazin-6-yl pyridinium betaine(4)in anhydrous pyridine.But when NaOH/H_2O/CH_3COCH_3 or NaOH/CH_3OH were used as reactant and solvent,3-methylthio-4-substituted benzenesulfonyl-5-oxo-6-hydroxy-1,4,5,6-tetrahydro-1,2,4-triazine(6)or 1-tosyl-3-methylthio-5-oxo-6-methyloxy-1,4,5,6-tetrahydro-1,2,4-triazine(7)was obtained respectively.The above reactions show anomalous properties of nucleophilic attack on 6-carbon in 1,2,4-triazine ring.