This paper proposes a secure approach for encryption and decryption of digital images with chaotic map lattices. In the proposed encryption process, eight different types of operations are used to encrypt the pixels o...This paper proposes a secure approach for encryption and decryption of digital images with chaotic map lattices. In the proposed encryption process, eight different types of operations are used to encrypt the pixels of an image and one of them will be used for particular pixels decided by the outcome of the chaotic map lattices. To make the cipher more robust against any attacks, the secret key is modified after encrypting each block of sixteen pixels of the image. The experimental results and security analysis show that the proposed image encryption scheme achieves high security and efficiency.展开更多
The Learning With Errors(LWE)problem is widely used in lattice-based cryptography,which is the most promising post-quantum cryptography direction.There are a variety of LWE-solving methods,which can be classified into...The Learning With Errors(LWE)problem is widely used in lattice-based cryptography,which is the most promising post-quantum cryptography direction.There are a variety of LWE-solving methods,which can be classified into four groups:lattice methods,algebraic methods,combinatorial methods,and exhaustive searching.The Blum–Kalai–Wasserman(BKW)algorithm is an important variety of combinatorial algorithms,which was first presented for solving the Learning Parity With Noise(LPN)problem and then extended to solve LWE.In this paper,we give an overview of BKW algorithms for solving LWE.We introduce the framework and key techniques of BKW algorithms and make comparisons between different BKW algorithms and also with lattice methods by estimating concrete security of specific LWE instances.We also briefly discuss the current problems and potential future directions of BKW algorithms.展开更多
Due to the rapid advancements in network technology,blockchain is being employed for distributed data storage.In the Internet of Things(IoT)scenario,different participants manage multiple blockchains located in differ...Due to the rapid advancements in network technology,blockchain is being employed for distributed data storage.In the Internet of Things(IoT)scenario,different participants manage multiple blockchains located in different trust domains,which has resulted in the extensive development of cross-domain authentication techniques.However,the emergence of many attackers equipped with quantum computers has the potential to launch quantum computing attacks against cross-domain authentication schemes based on traditional cryptography,posing a significant security threat.In response to the aforementioned challenges,our paper demonstrates a post-quantum cross-domain identity authentication scheme to negotiate the session key used in the cross-chain asset exchange process.Firstly,our paper designs the hiding and recovery process of user identity index based on lattice cryptography and introduces the identity-based signature from lattice to construct a post-quantum cross-domain authentication scheme.Secondly,our paper utilizes the hashed time-locked contract to achieves the cross-chain asset exchange of blockchain nodes in different trust domains.Furthermore,the security analysis reduces the security of the identity index and signature to Learning With Errors(LWE)and Short Integer Solution(SIS)assumption,respectively,indicating that our scheme has post-quantum security.Last but not least,through comparison analysis,we display that our scheme is efficient compared with the cross-domain authentication scheme based on traditional cryptography.展开更多
分析以往格上基于身份的全同态加密方案,指出方案效率低的根本原因在于陷门生成和原像采样过程的复杂度过高,为此提出一种新的解决方案。先将新型陷门函数与对偶容错学习(LWE,learning with errors)算法有机结合,构造一种新的格上基于...分析以往格上基于身份的全同态加密方案,指出方案效率低的根本原因在于陷门生成和原像采样过程的复杂度过高,为此提出一种新的解决方案。先将新型陷门函数与对偶容错学习(LWE,learning with errors)算法有机结合,构造一种新的格上基于身份的加密方案;再利用特征向量方法转化为格上基于身份的全同态加密方案。对比分析表明,所提方案的陷门生成复杂度显著降低,原像采样复杂度约降低为以往方案的1/3,SIVP近似因子缩小为以往方案的1/m^(1/2)。在标准模型下,方案安全性归约至判定性LWE的难解性,并包含严格的安全性证明。展开更多
With the increasing popularity of cloud storage,data security on the cloud has become increasingly visible.Searchable encryption has the ability to realize the privacy protection and security of data in the cloud.Howe...With the increasing popularity of cloud storage,data security on the cloud has become increasingly visible.Searchable encryption has the ability to realize the privacy protection and security of data in the cloud.However,with the continuous development of quantum computing,the standard Public-key Encryption with Keyword Search(PEKS)scheme cannot resist quantumbased keyword guessing attacks.Further,the credibility of the server also poses a significant threat to the security of the retrieval process.This paper proposes a searchable encryption scheme based on lattice cryptography using blockchain to address the above problems.Firstly,we design a lattice-based encryption primitive to resist quantum keyword guessing attacks.Moreover,blockchain is to decentralize the cloud storage platform’s jurisdiction of data.It also ensures that the traceability of keyword retrieval process and maintains the credibility of search result,which malicious platforms are prevented as much as possible from deliberately sending wrong search results.Last but not least,through security analysis,our proposed scheme satisfies the credibility and unforgeability of the keyword ciphertext.The comprehensive performance evaluates that our scheme has certain advantages in terms of efficiency compared with others.展开更多
Using lattice basis delegation in a fixed dimension, we propose an efficient lattice-based hierarchical identity based encryption（HIBE） scheme in the standard model whose public key size is only（dm^2＋ mn） log q b...Using lattice basis delegation in a fixed dimension, we propose an efficient lattice-based hierarchical identity based encryption（HIBE） scheme in the standard model whose public key size is only（dm^2＋ mn） log q bits and whose message-ciphertext expansion factor is only log q, where d is the maximum hierarchical depth and（n, m, q）are public parameters. In our construction, a novel public key assignment rule is used to averagely assign one random and public matrix to two identity bits, which implies that d random public matrices are enough to build the proposed HIBE scheme in the standard model, compared with the case in which 2d such public matrices are needed in the scheme proposed at Crypto 2010 whose public key size is（2dm^2＋ mn ＋ m） log q. To reduce the message-ciphertext expansion factor of the proposed scheme to log q, the encryption algorithm of this scheme is built based on Gentry＇s encryption scheme, by which m^2 bits of plaintext are encrypted into m^2 log q bits of ciphertext by a one time encryption operation. Hence, the presented scheme has some advantages with respect to not only the public key size but also the message-ciphertext expansion factor. Based on the hardness of the learning with errors problem, we demonstrate that the scheme is secure under selective identity and chosen plaintext attacks.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 61001099 and 10971120)the Foundation for the Author of National Excellent Doctoral Dissertation of China (Grant No. 200444)
文摘This paper proposes a secure approach for encryption and decryption of digital images with chaotic map lattices. In the proposed encryption process, eight different types of operations are used to encrypt the pixels of an image and one of them will be used for particular pixels decided by the outcome of the chaotic map lattices. To make the cipher more robust against any attacks, the secret key is modified after encrypting each block of sixteen pixels of the image. The experimental results and security analysis show that the proposed image encryption scheme achieves high security and efficiency.
基金supported by National Natural Science Foundation of China(No.U1936209).
文摘The Learning With Errors(LWE)problem is widely used in lattice-based cryptography,which is the most promising post-quantum cryptography direction.There are a variety of LWE-solving methods,which can be classified into four groups:lattice methods,algebraic methods,combinatorial methods,and exhaustive searching.The Blum–Kalai–Wasserman(BKW)algorithm is an important variety of combinatorial algorithms,which was first presented for solving the Learning Parity With Noise(LPN)problem and then extended to solve LWE.In this paper,we give an overview of BKW algorithms for solving LWE.We introduce the framework and key techniques of BKW algorithms and make comparisons between different BKW algorithms and also with lattice methods by estimating concrete security of specific LWE instances.We also briefly discuss the current problems and potential future directions of BKW algorithms.
基金This work was supported by the Defense Industrial Technology Development Program(Grant No.JCKY2021208B036).
文摘Due to the rapid advancements in network technology,blockchain is being employed for distributed data storage.In the Internet of Things(IoT)scenario,different participants manage multiple blockchains located in different trust domains,which has resulted in the extensive development of cross-domain authentication techniques.However,the emergence of many attackers equipped with quantum computers has the potential to launch quantum computing attacks against cross-domain authentication schemes based on traditional cryptography,posing a significant security threat.In response to the aforementioned challenges,our paper demonstrates a post-quantum cross-domain identity authentication scheme to negotiate the session key used in the cross-chain asset exchange process.Firstly,our paper designs the hiding and recovery process of user identity index based on lattice cryptography and introduces the identity-based signature from lattice to construct a post-quantum cross-domain authentication scheme.Secondly,our paper utilizes the hashed time-locked contract to achieves the cross-chain asset exchange of blockchain nodes in different trust domains.Furthermore,the security analysis reduces the security of the identity index and signature to Learning With Errors(LWE)and Short Integer Solution(SIS)assumption,respectively,indicating that our scheme has post-quantum security.Last but not least,through comparison analysis,we display that our scheme is efficient compared with the cross-domain authentication scheme based on traditional cryptography.
文摘分析以往格上基于身份的全同态加密方案,指出方案效率低的根本原因在于陷门生成和原像采样过程的复杂度过高,为此提出一种新的解决方案。先将新型陷门函数与对偶容错学习(LWE,learning with errors)算法有机结合,构造一种新的格上基于身份的加密方案;再利用特征向量方法转化为格上基于身份的全同态加密方案。对比分析表明,所提方案的陷门生成复杂度显著降低,原像采样复杂度约降低为以往方案的1/3,SIVP近似因子缩小为以往方案的1/m^(1/2)。在标准模型下,方案安全性归约至判定性LWE的难解性,并包含严格的安全性证明。
基金This work was supported by the Open Fund of Advanced Cryptography and System Security Key Laboratory of Sichuan Province(Grant No.SKLACSS-202101)NSFC(Grant Nos.62176273,61962009,U1936216)+3 种基金the Foundation of Guizhou Provincial Key Laboratory of Public Big Data(No.2019BDKFJJ010,2019BDKFJJ014)the Fundamental Research Funds for Beijing Municipal Commission of Education,Beijing Urban Governance Research Base of North China University of Technology,the Natural Science Foundation of Inner Mongolia(2021MS06006)Baotou Kundulun District Science and technology plan project(YF2020013)Inner Mongolia discipline inspection and supervision big data laboratory open project fund(IMDBD2020020).
文摘With the increasing popularity of cloud storage,data security on the cloud has become increasingly visible.Searchable encryption has the ability to realize the privacy protection and security of data in the cloud.However,with the continuous development of quantum computing,the standard Public-key Encryption with Keyword Search(PEKS)scheme cannot resist quantumbased keyword guessing attacks.Further,the credibility of the server also poses a significant threat to the security of the retrieval process.This paper proposes a searchable encryption scheme based on lattice cryptography using blockchain to address the above problems.Firstly,we design a lattice-based encryption primitive to resist quantum keyword guessing attacks.Moreover,blockchain is to decentralize the cloud storage platform’s jurisdiction of data.It also ensures that the traceability of keyword retrieval process and maintains the credibility of search result,which malicious platforms are prevented as much as possible from deliberately sending wrong search results.Last but not least,through security analysis,our proposed scheme satisfies the credibility and unforgeability of the keyword ciphertext.The comprehensive performance evaluates that our scheme has certain advantages in terms of efficiency compared with others.
基金Project supported by the National Natural Science Foundation of China（Nos.61303198,61471409,61472470,and 61402112） the Natural Science Foundation of Shandong Province,China（No.ZR2013FQ031）
文摘Using lattice basis delegation in a fixed dimension, we propose an efficient lattice-based hierarchical identity based encryption（HIBE） scheme in the standard model whose public key size is only（dm^2＋ mn） log q bits and whose message-ciphertext expansion factor is only log q, where d is the maximum hierarchical depth and（n, m, q）are public parameters. In our construction, a novel public key assignment rule is used to averagely assign one random and public matrix to two identity bits, which implies that d random public matrices are enough to build the proposed HIBE scheme in the standard model, compared with the case in which 2d such public matrices are needed in the scheme proposed at Crypto 2010 whose public key size is（2dm^2＋ mn ＋ m） log q. To reduce the message-ciphertext expansion factor of the proposed scheme to log q, the encryption algorithm of this scheme is built based on Gentry＇s encryption scheme, by which m^2 bits of plaintext are encrypted into m^2 log q bits of ciphertext by a one time encryption operation. Hence, the presented scheme has some advantages with respect to not only the public key size but also the message-ciphertext expansion factor. Based on the hardness of the learning with errors problem, we demonstrate that the scheme is secure under selective identity and chosen plaintext attacks.
