针对现有Niederreiter公钥密码方案容易遭受区分攻击和信息集攻击(ISD)的现状,提出一种改进的Niederreiter公钥密码方案。首先,对Niederreiter公钥密码方案中的置换矩阵进行了改进,把原有的置换矩阵替换为随机矩阵;其次,对Niederreiter...针对现有Niederreiter公钥密码方案容易遭受区分攻击和信息集攻击(ISD)的现状,提出一种改进的Niederreiter公钥密码方案。首先,对Niederreiter公钥密码方案中的置换矩阵进行了改进,把原有的置换矩阵替换为随机矩阵;其次,对Niederreiter公钥密码方案中的错误向量进行了随机拆分,隐藏错误向量的汉明重量;最后,对Niederreiter公钥密码方案的加解密过程进行了改进,以提高方案的安全性。分析表明,改进方案可以抵抗区分攻击和ISD;改进方案的公钥量小于Baldi等提出的方案(BALDI M,BIANCHI M,CHIARALUCE F,et al.Enhanced public key security for the Mc Eliece cryptosystem.Journal of Cryptology,2016,29(1):1-27)的公钥量,在80比特的安全级下,改进方案的公钥量从原方案的28 408比特降低到4 800比特;在128比特的安全级下,改进方案的公钥量从原方案的57 368比特降低到12 240比特。作为抗量子密码方案之一,改进方案的生存力和竞争力增强。展开更多
A joint signature,encryption and error correction public-key cryptosystem is pre-sented based on an NP-completeness problem-the decoding problem of general linear codes inalgebraic coding theory,
The real polynomial type public-key cryptosystems are broken up by computing the equivalent secure keys, then some computational problems related to securities of cryptosystems are discussed.
Based on the characteristic of key-insulated public-key cryptosystem, wepropose a distributed landora session keys distribution protocol without a key distribution center.The session key is generated by different user...Based on the characteristic of key-insulated public-key cryptosystem, wepropose a distributed landora session keys distribution protocol without a key distribution center.The session key is generated by different user and only used one time. So thekey is one-time key. Inaddition, the user who generates the next one-time key, is random selected by the current sessionkey. In the protocol of this paper, the characteristic of time in the key-insulated public-key, adistributed protocol, translates into the characteristic of spaee which every point has differentsecret key in the different period. At the same time, the system is fit for key management in AdHoe, and is a new scheme of key management in Ad Hoc.展开更多
The most popular present-day public-key cryptosystems are RSA and ElGamal cryptosystems. Some practical algebraic generalization of the ElGamal cryptosystem is considered-basic modular matrix cryptosystem (BMMC) over ...The most popular present-day public-key cryptosystems are RSA and ElGamal cryptosystems. Some practical algebraic generalization of the ElGamal cryptosystem is considered-basic modular matrix cryptosystem (BMMC) over the modular matrix ring M2(Zn). An example of computation for an artificially small number n is presented. Some possible attacks on the cryptosystem and mathematical problems, the solution of which are necessary for implementing these attacks, are studied. For a small number n, computational time for compromising some present-day public-key cryptosystems such as RSA, ElGamal, and Rabin, is compared with the corresponding time for the ВММС. Finally, some open mathematical and computational problems are formulated.展开更多
Timing attack is an attack on the implementation of a cryptographic primitive. The attack collects leaked secret data via certain implementation techniques either on software or hardware. This paper provides an analys...Timing attack is an attack on the implementation of a cryptographic primitive. The attack collects leaked secret data via certain implementation techniques either on software or hardware. This paper provides an analysis of a theoretical timing attack on the AAβ algorithm. The attack discussed in this paper gives avenues for secure implementation of AAβ against timing attacks. The simulation of the attack is important to provide invulnerability features for the algorithm in order to be implemented and embedded on applications. At the end of the attack, a method to overcome it will be introduced and it is called AAβ blinding.展开更多
The concept of sharing of personal health data over cloud storage in a healthcare-cyber physical system has become popular in recent times as it improves access quality.The privacy of health data can only be preserved...The concept of sharing of personal health data over cloud storage in a healthcare-cyber physical system has become popular in recent times as it improves access quality.The privacy of health data can only be preserved by keeping it in an encrypted form,but it affects usability and flexibility in terms of effective search.Attribute-based searchable encryption(ABSE)has proven its worth by providing fine-grained searching capabilities in the shared cloud storage.However,it is not practical to apply this scheme to the devices with limited resources and storage capacity because a typical ABSE involves serious computations.In a healthcare cloud-based cyber-physical system(CCPS),the data is often collected by resource-constraint devices;therefore,here also,we cannot directly apply ABSE schemes.In the proposed work,the inherent computational cost of the ABSE scheme is managed by executing the computationally intensive tasks of a typical ABSE scheme on the blockchain network.Thus,it makes the proposed scheme suitable for online storage and retrieval of personal health data in a typical CCPS.With the assistance of blockchain technology,the proposed scheme offers two main benefits.First,it is free from a trusted authority,which makes it genuinely decentralized and free from a single point of failure.Second,it is computationally efficient because the computational load is now distributed among the consensus nodes in the blockchain network.Specifically,the task of initializing the system,which is considered the most computationally intensive,and the task of partial search token generation,which is considered as the most frequent operation,is now the responsibility of the consensus nodes.This eliminates the need of the trusted authority and reduces the burden of data users,respectively.Further,in comparison to existing decentralized fine-grained searchable encryption schemes,the proposed scheme has achieved a significant reduction in storage and computational cost for the secret key associated with users.It has been verified both theoretically and practically in the performance analysis section.展开更多
Okamoto public-key cryptosystem (abbr. OPKC)has drawn considerable attention for its convenience and rapidity of encryption and decryption. K. Koyama, A.Shamir, B. Vallee and others already analyzed it and presented s...Okamoto public-key cryptosystem (abbr. OPKC)has drawn considerable attention for its convenience and rapidity of encryption and decryption. K. Koyama, A.Shamir, B. Vallee and others already analyzed it and presented some attacks. This report gives OPKC an elementary attack, which can not only break completely both the systems of OPKC but also be used to attack other public-key cryptosystems similar to OPKC, such as展开更多
In this paper an encryption-decryption algorithm based on two moduli is described: one in the real field of integers and another in the field of complex integers. Also the proper selection of cryptographic system para...In this paper an encryption-decryption algorithm based on two moduli is described: one in the real field of integers and another in the field of complex integers. Also the proper selection of cryptographic system parameters is described. Several numeric illustrations explain step-by-step how to precondition a plaintext, how to select secret control parameters, how to ensure feasibility of all private keys and how to avoid ambiguity in the process of information recovery. The proposed cryptographic system is faster than most of known public key cryptosystems, since it requires a small number of multiplications and additions, and does not require exponentiations for its implementation.展开更多
文摘针对现有Niederreiter公钥密码方案容易遭受区分攻击和信息集攻击(ISD)的现状,提出一种改进的Niederreiter公钥密码方案。首先,对Niederreiter公钥密码方案中的置换矩阵进行了改进,把原有的置换矩阵替换为随机矩阵;其次,对Niederreiter公钥密码方案中的错误向量进行了随机拆分,隐藏错误向量的汉明重量;最后,对Niederreiter公钥密码方案的加解密过程进行了改进,以提高方案的安全性。分析表明,改进方案可以抵抗区分攻击和ISD;改进方案的公钥量小于Baldi等提出的方案(BALDI M,BIANCHI M,CHIARALUCE F,et al.Enhanced public key security for the Mc Eliece cryptosystem.Journal of Cryptology,2016,29(1):1-27)的公钥量,在80比特的安全级下,改进方案的公钥量从原方案的28 408比特降低到4 800比特;在128比特的安全级下,改进方案的公钥量从原方案的57 368比特降低到12 240比特。作为抗量子密码方案之一,改进方案的生存力和竞争力增强。
基金Subject supported by the National Natural Science Fund of China
文摘A joint signature,encryption and error correction public-key cryptosystem is pre-sented based on an NP-completeness problem-the decoding problem of general linear codes inalgebraic coding theory,
基金Supported by the National Natural Science Foundation of Chinathe Fund of the State Education Commission of China
文摘The real polynomial type public-key cryptosystems are broken up by computing the equivalent secure keys, then some computational problems related to securities of cryptosystems are discussed.
文摘Based on the characteristic of key-insulated public-key cryptosystem, wepropose a distributed landora session keys distribution protocol without a key distribution center.The session key is generated by different user and only used one time. So thekey is one-time key. Inaddition, the user who generates the next one-time key, is random selected by the current sessionkey. In the protocol of this paper, the characteristic of time in the key-insulated public-key, adistributed protocol, translates into the characteristic of spaee which every point has differentsecret key in the different period. At the same time, the system is fit for key management in AdHoe, and is a new scheme of key management in Ad Hoc.
文摘The most popular present-day public-key cryptosystems are RSA and ElGamal cryptosystems. Some practical algebraic generalization of the ElGamal cryptosystem is considered-basic modular matrix cryptosystem (BMMC) over the modular matrix ring M2(Zn). An example of computation for an artificially small number n is presented. Some possible attacks on the cryptosystem and mathematical problems, the solution of which are necessary for implementing these attacks, are studied. For a small number n, computational time for compromising some present-day public-key cryptosystems such as RSA, ElGamal, and Rabin, is compared with the corresponding time for the ВММС. Finally, some open mathematical and computational problems are formulated.
文摘Timing attack is an attack on the implementation of a cryptographic primitive. The attack collects leaked secret data via certain implementation techniques either on software or hardware. This paper provides an analysis of a theoretical timing attack on the AAβ algorithm. The attack discussed in this paper gives avenues for secure implementation of AAβ against timing attacks. The simulation of the attack is important to provide invulnerability features for the algorithm in order to be implemented and embedded on applications. At the end of the attack, a method to overcome it will be introduced and it is called AAβ blinding.
文摘The concept of sharing of personal health data over cloud storage in a healthcare-cyber physical system has become popular in recent times as it improves access quality.The privacy of health data can only be preserved by keeping it in an encrypted form,but it affects usability and flexibility in terms of effective search.Attribute-based searchable encryption(ABSE)has proven its worth by providing fine-grained searching capabilities in the shared cloud storage.However,it is not practical to apply this scheme to the devices with limited resources and storage capacity because a typical ABSE involves serious computations.In a healthcare cloud-based cyber-physical system(CCPS),the data is often collected by resource-constraint devices;therefore,here also,we cannot directly apply ABSE schemes.In the proposed work,the inherent computational cost of the ABSE scheme is managed by executing the computationally intensive tasks of a typical ABSE scheme on the blockchain network.Thus,it makes the proposed scheme suitable for online storage and retrieval of personal health data in a typical CCPS.With the assistance of blockchain technology,the proposed scheme offers two main benefits.First,it is free from a trusted authority,which makes it genuinely decentralized and free from a single point of failure.Second,it is computationally efficient because the computational load is now distributed among the consensus nodes in the blockchain network.Specifically,the task of initializing the system,which is considered the most computationally intensive,and the task of partial search token generation,which is considered as the most frequent operation,is now the responsibility of the consensus nodes.This eliminates the need of the trusted authority and reduces the burden of data users,respectively.Further,in comparison to existing decentralized fine-grained searchable encryption schemes,the proposed scheme has achieved a significant reduction in storage and computational cost for the secret key associated with users.It has been verified both theoretically and practically in the performance analysis section.
基金Project supported by the National Natural Science Foundation of China.
文摘Okamoto public-key cryptosystem (abbr. OPKC)has drawn considerable attention for its convenience and rapidity of encryption and decryption. K. Koyama, A.Shamir, B. Vallee and others already analyzed it and presented some attacks. This report gives OPKC an elementary attack, which can not only break completely both the systems of OPKC but also be used to attack other public-key cryptosystems similar to OPKC, such as
文摘In this paper an encryption-decryption algorithm based on two moduli is described: one in the real field of integers and another in the field of complex integers. Also the proper selection of cryptographic system parameters is described. Several numeric illustrations explain step-by-step how to precondition a plaintext, how to select secret control parameters, how to ensure feasibility of all private keys and how to avoid ambiguity in the process of information recovery. The proposed cryptographic system is faster than most of known public key cryptosystems, since it requires a small number of multiplications and additions, and does not require exponentiations for its implementation.
