When developing programs or websites, it is very convenient to use relational databases, which contain powerful and convenient tools that allow to work with data very flexibly and get the necessary information in a ma...When developing programs or websites, it is very convenient to use relational databases, which contain powerful and convenient tools that allow to work with data very flexibly and get the necessary information in a matter of milliseconds. A relational database consists of tables and records in these tables, each table must have a primary key, in particular, it can be a number of BIGINT type, which is a unique index of a record in the table, which allows to fetch operation with maximum speed and O (1) complexity. After the operation of writing a row to the table of database, the program receives the row identifier ID in the form of a number, and in the future this ID can be used to obtain this record. In the case of a website, this could be the GET method of the http protocol with the entry ID in the request. But very often it happens that the transmission of an identifier in the clear form is not safe, both for business reasons and for security reasons of access to information. And in this case, it is necessary to create additional functionality for checking access rights and come up with a way to encode data in such a way that it would be impossible to determine the record identifier, and this, in turn, leads to the fact that the program code becomes much more complicated and also increases the amount of data, necessary to ensure the operation of the program. This article presents an algorithm that solves these problems “on the fly” without complicating the application logic and does not require resources to store additional information. Also, this algorithm is very reliable since it is based on the use of hash functions and synthesized as a result of many years of work related to writing complex systems that require an increased level of data security and program performance.展开更多
In order to meet the needs of higher operation speed and lower energy consumption an optimized SHA-1 algorithm is proposed.It combines two methods loop-unfolding and pre-processing.In the process intermediate variable...In order to meet the needs of higher operation speed and lower energy consumption an optimized SHA-1 algorithm is proposed.It combines two methods loop-unfolding and pre-processing.In the process intermediate variables are introduced in the iterations and pre-calculated so that the original single-threading operation can perform in a multi-threading way.This optimized algorithm exploits parallelism to shorten the critical path for hash operations.And the cycles of the original algorithm are reduced from 80 to 41 which greatly improves the operation speed.Therefore the shortened iterations of the optimized design require a smaller amount of hardware resource thus achieving a lower energy consumption. The optimized algorithm is implemented on FPGA field programmable gate array .It can achieve a throughput rate of 1.2 Gbit /s with the maximum clock frequency of 91 MHz reaching a fair balance between operation speed and throughput rate.The simulation results show that compared with other optimized SHA-1 algorithms this algorithm obtains higher operation speed and throughput rate without compromising the security of the original SHA-1 algorithm.展开更多
The collision and statistical properties of a one-way hash function based on spatiotemporal chaos are investigated. Analysis and simulation results indicate that collisions exist in the original algorithm and, therefo...The collision and statistical properties of a one-way hash function based on spatiotemporal chaos are investigated. Analysis and simulation results indicate that collisions exist in the original algorithm and, therefore, the original algorithm is insecure and vulnerable. An improved algorithm is proposed to avoid the collisions.展开更多
The design of an efficient one-way hash function with good performance is a hot spot in modern cryptography researches. In this paper, a hash function construction method based on cell neural network with hyper-chaos ...The design of an efficient one-way hash function with good performance is a hot spot in modern cryptography researches. In this paper, a hash function construction method based on cell neural network with hyper-chaos characteristics is proposed. First, the chaos sequence is gotten by iterating cellular neural network with Runge Kutta algorithm, and then the chaos sequence is iterated with the message. The hash code is obtained through the corre- sponding transform of the latter chaos sequence. Simulation and analysis demonstrate that the new method has the merit of convenience, high sensitivity to initial values, good hash performance, especially the strong stability.展开更多
A novel scheme to construct a hash function based on a weighted complex dynamical network (WCDN) generated from an original message is proposed in this paper. First, the original message is divided into blocks. Then...A novel scheme to construct a hash function based on a weighted complex dynamical network (WCDN) generated from an original message is proposed in this paper. First, the original message is divided into blocks. Then, each block is divided into components, and the nodes and weighted edges are well defined from these components and their relations. Namely, the WCDN closely related to the original message is established. Furthermore, the node dynamics of the WCDN are chosen as a chaotic map. After chaotic iterations, quantization and exclusive-or operations, the fixed-length hash value is obtained. This scheme has the property that any tiny change in message can be diffused rapidly through the WCDN, leading to very different hash values. Analysis and simulation show that the scheme possesses good statistical properties, excellent confusion and diffusion, strong collision resistance and high efficiency.展开更多
A new one-way hash function based on the unified chaotic system is constructed. With different values of a key parameter, the unified chaotic system represents different chaotic systems, based on which the one-way has...A new one-way hash function based on the unified chaotic system is constructed. With different values of a key parameter, the unified chaotic system represents different chaotic systems, based on which the one-way hash function algorithm is constructed with three round operations and an initial vector on an input message. In each round operation, the parameters are processed by three different chaotic systems generated from the unified chaotic system. Feed-forwards are used at the end of each round operation and at the end of each element of the message processing. Meanwhile, in each round operation, parameter-exchanging operations are implemented. Then, the hash value of length 160 bits is obtained from the last six parameters. Simulation and analysis both demonstrate that the algorithm has great flexibility, satisfactory hash performance, weak collision property, and high security.展开更多
A new Hash function based on the generalized Henon map is proposed. We have obtained a binary sequence with excellent pseudo-random characteristics through improving the sequence generated by the generalized Henon map...A new Hash function based on the generalized Henon map is proposed. We have obtained a binary sequence with excellent pseudo-random characteristics through improving the sequence generated by the generalized Henon map, and use it to construct Hash function. First we divide the message into groups, and then carry out the Xor operation between the ASCII value of each group and the binary sequence, the result can be used as the initial values of the next loop. Repeat the procedure until all the groups have been processed, and the final binary sequence is the Hash value. In the scheme, the initial values of the generalized Henon map are used as the secret key and the messages are mapped to Hash values with a designated length. Simulation results show that the proposed scheme has strong diffusion and confusion capability, good collision resistance, large key space, extreme sensitivity to message and secret key, and it is easy to be realized and extended.展开更多
To ensure the security during the communication,we often adopt different ways to encrypt the messages to resist various attacks.However,with the computing power improving,the existing encryption and authentication sch...To ensure the security during the communication,we often adopt different ways to encrypt the messages to resist various attacks.However,with the computing power improving,the existing encryption and authentication schemes are being faced with big challenges.We take the message authentication as an example into a careful consideration.Then,we proposed a new message authentication scheme with the Advanced Encryption Standard as the encryption function and the new quantum Hash function as the authentication function.Firstly,the Advanced Encryption Standard algorithm is used to encrypt the result of the initial message cascading the corresponding Hash values,which ensures that the initial message can resist eavesdropping attack.Secondly,utilizing the new quantum Hash function with quantum walks can be much more secure than traditional classical Hash functions with keeping the common properties,such as one-wayness,resisting different collisions and easy implementation.Based on these two points,the message authentication scheme can be much more secure than previous ones.Finally,it is a new way to design the message authentication scheme,which provides a new thought for other researchers in the future.Our works will contribute to the study on the new encryption and authentication functions and the combination of quantum computing with traditional cryptology in the future.展开更多
A new algorithm for a novel hash function, based on chaotic tent map with changeable parameter, is proposed and analyzed. The one dimensional and piecewise tent map with changeable parameters decided by the position i...A new algorithm for a novel hash function, based on chaotic tent map with changeable parameter, is proposed and analyzed. The one dimensional and piecewise tent map with changeable parameters decided by the position index of blocked messages is chosen, and blocked massages translated into ASCII code values are employed as the iteration time of the chaotic tent map. The final 128-bit hash value is generated by logical XOR operation on intermediate hash values. Theoretical analysis and computer simulation indicate that the proposed algorithm can satisfy the performance requirements of hash function.展开更多
Message integrity is found to prove the transfer information of patient in health care monitoring system on the human body in order to collect and communicate the human personal data. Wireless body area network (WBAN)...Message integrity is found to prove the transfer information of patient in health care monitoring system on the human body in order to collect and communicate the human personal data. Wireless body area network (WBAN) applications are the fast growing technology trend but security and privacy are still largely ignored, since they are hard to achieve given the limited computation and energy resources available at sensor node level. In this paper, we propose simple hash based message authentication and integrity code algorithm for wireless sensor networks. We test the proposed algorithm in MATLAB on path loss model around the human body in two scenarios and compare the result before and after enhancement and show how sensors are connected with each other to prove the message integrity in monitoring health environment.展开更多
Sorting the Tibetan language quickly and accurately requires first identifying the component elements that make up Tibetan syllables and then sorting by the priority of the component.Based on the study of Tibetan text...Sorting the Tibetan language quickly and accurately requires first identifying the component elements that make up Tibetan syllables and then sorting by the priority of the component.Based on the study of Tibetan text structure,grammatical rules and syllable structure,we present a structurebased Tibetan syllable recognition method that uses syllable structure instead of grammar.This method avoids complicated Tibetan grammar and recognizes the components of Tibetan syllables simply and quickly.On the basis of identifying the components of Tibetan syllables,a Tibetan syllable sorting algorithm that conforms to the language sorting rules is proposed.The core of the Tibetan syllable sorting algorithm is a hash function.Research has found that the sorting of all legal Tibetan syllables requires eight components of information.The hash function is based on this discovery and can be assigned corresponding weights according to different sorting verify the effectiveness of the Tibetan sorting algorithm,we established an experimental corpus using the Tibetan sorting standard document recognized by the majority of Tibetan users,namely the New Tibetan Orthographic Dictionary.Experiments show that this method produces results completely consistent with standard reference works,with an accuracy of 100%,and with minimal computational time.展开更多
Based on the spatiotemporal chaotic system, a novel algorithm for constructing a one-way hash function is proposed and analysed. The message is divided into fixed length blocks. Each message block is processed by the ...Based on the spatiotemporal chaotic system, a novel algorithm for constructing a one-way hash function is proposed and analysed. The message is divided into fixed length blocks. Each message block is processed by the hash compression function in parallel. The hash compression is constructed based on the spatiotemporal chaos. In each message block, the ASCII code and its position in the whole message block chain constitute the initial conditions and the key of the hash compression function. The final hash value is generated by further compressing the mixed result of all the hash compression vulues. Theoretic analyses and numerical simulations show that the proposed algorithm presents high sensitivity to the message and key, good statistical properties, and strong collision resistance.展开更多
Hash functions are often used in the authentication of information security field. With the development of electronic commerce, the reliability of authentication is paid more and more attention to. This paper describe...Hash functions are often used in the authentication of information security field. With the development of electronic commerce, the reliability of authentication is paid more and more attention to. This paper describes an N - LFSR which combined nonlinear S - box with the LF-SR, and substitutes it for CLS operator in hash function. The efficiency of new hash function is not drop and the ability of defence attack is strengthened.展开更多
In this paper,based on coupled network generated by chaotic logarithmic map,a novel algorithm for constructing hash functions is proposed,which can transform messages and can establish a mapping from the transformed m...In this paper,based on coupled network generated by chaotic logarithmic map,a novel algorithm for constructing hash functions is proposed,which can transform messages and can establish a mapping from the transformed messages to the coupled matrix of the network.The network model is carefully designed to ensure the network dynamics to be chaotic.Through the chaotic iterations of the network,quantization and exclusive-or (XOR) operations,the algorithm can construct hash value with arbitrary length.It is shown by simulations that the algorithm is extremely sensitive to the initial values and the coupled matrix of the network,and has excellent performance in one-way,confusion and diffusion,and collision resistance.展开更多
The design of a chaotic image encryption algorithm plays an essential role in enhancing information and communication security.The performance of such algorithms is intricately linked to the complexity of the chaotic ...The design of a chaotic image encryption algorithm plays an essential role in enhancing information and communication security.The performance of such algorithms is intricately linked to the complexity of the chaotic sequence and the underlying encryption algorithm.To additionally enhance the complexity of hyperchaotic systems,this study presents a novel construction of a Five-Dimensional(5D)memristive hyperchaotic system through the introduction of the flux-controlled memristor model.The system's dynamic characteristics are examined through various analytical methods,including phase portraits,bifurcation diagrams,and Lyapunov exponent spectra.Accordingly,the sequences produced by the hyperchaotic system,which passed the National Institute of Standards and Technology(NIST)test,are employed to inform the creation of a novelty image encryption technique that combines hash function,Deoxyribonucleic Acid(DNA)encoding,logistic,and Two-Dimensional Hyperchaotic Map(2D-SFHM).It improves the sensitivity of key and plaintext images to image encryption,expands the algorithm key space,and increases the complexity of the encryption algorithm.Experimental findings and analysis validate the exceptional encryption capabilities of the novel algorithm.The algorithm exhibits a considerable key space 2512,and the ciphertext image demonstrates an information entropy of 7.9994,with inter-pixel correlation approaching zero,etc.,showcasing its resilience against different types of attacks on images.展开更多
In this paper, we present a fast attack algorithm to find two-block collision of hash function MD5. The algorithm is based on the two-block collision differential path of MD5 that was presented by Wang et al. in the C...In this paper, we present a fast attack algorithm to find two-block collision of hash function MD5. The algorithm is based on the two-block collision differential path of MD5 that was presented by Wang et al. in the Conference EUROCRYPT 2005. We found that the derived conditions for the desired collision differential path were not sufficient to guarantee the path to hold and that some conditions could be modified to enlarge the collision set. By using technique of small range searching and omitting the computing steps to check the characteristics in the attack algorithm, we can speed up the attack of MD5 efficiently. Compared with the Advanced Message Modification technique presented by Wang et al., the small range searching technique can correct 4 more conditions for the first iteration differential and 3 more conditions for the second iteration differential, thus improving the probability and the complexity to find collisions. The whole attack on the MD5 can be accomplished within 5 hours using a PC with Pentium4 1.70GHz CPU.展开更多
Abstract In this paper, we give a fast attack against hash function HAVAL-128. HAVAL was presented by Y. L. Zheng et al. at Auscrypto'92. It can be processed in 3, 4 or 5 passes, and produces 128, 160, 192, or 224-bi...Abstract In this paper, we give a fast attack against hash function HAVAL-128. HAVAL was presented by Y. L. Zheng et al. at Auscrypto'92. It can be processed in 3, 4 or 5 passes, and produces 128, 160, 192, or 224-bit fingerprint. We break the HAVAL with 128-bit fingerprint. The conclusion is that, given any 1024-bit message ra, we just make some modifications about m, and the modified message ra can collide with another message m only with probability 1/2^7, where m = m + △m, in which △m is a fixed difference selected in advance. In addition, two collision examples for HAVAL-128 are given in this paper.展开更多
Research on existing radio frequency identification(RFID) authentication protocols security risks, poor performance and other problems, a RFID security authentication protocol based on dynamic identification(ID) a...Research on existing radio frequency identification(RFID) authentication protocols security risks, poor performance and other problems, a RFID security authentication protocol based on dynamic identification(ID) and Key value renewal is proposed. Meanwhile, the security problems based on Hash function RFID security authentication protocol in recent years have been also sorted and analyzed. Then a security model to design and analyze RFID protocols is built. By using the computational complexity, its correctness and security have been proved. Compared with the safety performance, storage overhead, computational overhead and other aspects of other protocols, the protocol for RFID has more efficient performance and ability to withstand various attacks. And the C# programming language is used to simulate the authentication process on the visual studio platform, which verifies the feasibility of the protocol.展开更多
文摘When developing programs or websites, it is very convenient to use relational databases, which contain powerful and convenient tools that allow to work with data very flexibly and get the necessary information in a matter of milliseconds. A relational database consists of tables and records in these tables, each table must have a primary key, in particular, it can be a number of BIGINT type, which is a unique index of a record in the table, which allows to fetch operation with maximum speed and O (1) complexity. After the operation of writing a row to the table of database, the program receives the row identifier ID in the form of a number, and in the future this ID can be used to obtain this record. In the case of a website, this could be the GET method of the http protocol with the entry ID in the request. But very often it happens that the transmission of an identifier in the clear form is not safe, both for business reasons and for security reasons of access to information. And in this case, it is necessary to create additional functionality for checking access rights and come up with a way to encode data in such a way that it would be impossible to determine the record identifier, and this, in turn, leads to the fact that the program code becomes much more complicated and also increases the amount of data, necessary to ensure the operation of the program. This article presents an algorithm that solves these problems “on the fly” without complicating the application logic and does not require resources to store additional information. Also, this algorithm is very reliable since it is based on the use of hash functions and synthesized as a result of many years of work related to writing complex systems that require an increased level of data security and program performance.
基金The Project of Wireless Intelligence Terminal Inspection Services(No.6704000084)the Special Program of the NationalDevelopment and Reform Committee
文摘In order to meet the needs of higher operation speed and lower energy consumption an optimized SHA-1 algorithm is proposed.It combines two methods loop-unfolding and pre-processing.In the process intermediate variables are introduced in the iterations and pre-calculated so that the original single-threading operation can perform in a multi-threading way.This optimized algorithm exploits parallelism to shorten the critical path for hash operations.And the cycles of the original algorithm are reduced from 80 to 41 which greatly improves the operation speed.Therefore the shortened iterations of the optimized design require a smaller amount of hardware resource thus achieving a lower energy consumption. The optimized algorithm is implemented on FPGA field programmable gate array .It can achieve a throughput rate of 1.2 Gbit /s with the maximum clock frequency of 91 MHz reaching a fair balance between operation speed and throughput rate.The simulation results show that compared with other optimized SHA-1 algorithms this algorithm obtains higher operation speed and throughput rate without compromising the security of the original SHA-1 algorithm.
基金Project supported by the National Natural Science Foundation of China (Grant No.60973109)
文摘The collision and statistical properties of a one-way hash function based on spatiotemporal chaos are investigated. Analysis and simulation results indicate that collisions exist in the original algorithm and, therefore, the original algorithm is insecure and vulnerable. An improved algorithm is proposed to avoid the collisions.
基金supported by Key Program of Natural Science Fund of Tianjin of China (Grant No 07JCZDJC06600)
文摘The design of an efficient one-way hash function with good performance is a hot spot in modern cryptography researches. In this paper, a hash function construction method based on cell neural network with hyper-chaos characteristics is proposed. First, the chaos sequence is gotten by iterating cellular neural network with Runge Kutta algorithm, and then the chaos sequence is iterated with the message. The hash code is obtained through the corre- sponding transform of the latter chaos sequence. Simulation and analysis demonstrate that the new method has the merit of convenience, high sensitivity to initial values, good hash performance, especially the strong stability.
基金Project supported by the Natural Science Foundation of Jiangsu Province, China (Grant No. BK2010526)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20103223110003)The Ministry of Education Research in the Humanities and Social Sciences Planning Fund, China (Grant No. 12YJAZH120)
文摘A novel scheme to construct a hash function based on a weighted complex dynamical network (WCDN) generated from an original message is proposed in this paper. First, the original message is divided into blocks. Then, each block is divided into components, and the nodes and weighted edges are well defined from these components and their relations. Namely, the WCDN closely related to the original message is established. Furthermore, the node dynamics of the WCDN are chosen as a chaotic map. After chaotic iterations, quantization and exclusive-or operations, the fixed-length hash value is obtained. This scheme has the property that any tiny change in message can be diffused rapidly through the WCDN, leading to very different hash values. Analysis and simulation show that the scheme possesses good statistical properties, excellent confusion and diffusion, strong collision resistance and high efficiency.
基金Project supported by the Natural Science Foundation of Hunan Province,China (Grant No 08JJ4020)
文摘A new one-way hash function based on the unified chaotic system is constructed. With different values of a key parameter, the unified chaotic system represents different chaotic systems, based on which the one-way hash function algorithm is constructed with three round operations and an initial vector on an input message. In each round operation, the parameters are processed by three different chaotic systems generated from the unified chaotic system. Feed-forwards are used at the end of each round operation and at the end of each element of the message processing. Meanwhile, in each round operation, parameter-exchanging operations are implemented. Then, the hash value of length 160 bits is obtained from the last six parameters. Simulation and analysis both demonstrate that the algorithm has great flexibility, satisfactory hash performance, weak collision property, and high security.
基金supported by the National Natural Science Foundation of China (Grant No 60372061)
文摘A new Hash function based on the generalized Henon map is proposed. We have obtained a binary sequence with excellent pseudo-random characteristics through improving the sequence generated by the generalized Henon map, and use it to construct Hash function. First we divide the message into groups, and then carry out the Xor operation between the ASCII value of each group and the binary sequence, the result can be used as the initial values of the next loop. Repeat the procedure until all the groups have been processed, and the final binary sequence is the Hash value. In the scheme, the initial values of the generalized Henon map are used as the secret key and the messages are mapped to Hash values with a designated length. Simulation results show that the proposed scheme has strong diffusion and confusion capability, good collision resistance, large key space, extreme sensitivity to message and secret key, and it is easy to be realized and extended.
基金Project supported by NSFC(Grant Nos.U1836205,61702040)the Major Scientific and Technological Special Project of Guizhou Province(Grant No.20183001)+2 种基金the Foundation of Guizhou Provincial Key Laboratory of Public Big Data(Grant No.2018BDKFJJ016)the Foundation of State Key Laboratory of Public Big Data(Grant No.2018BDKFJJ018)Beijing Natural Science Foundation(Grant No.4174089).
文摘To ensure the security during the communication,we often adopt different ways to encrypt the messages to resist various attacks.However,with the computing power improving,the existing encryption and authentication schemes are being faced with big challenges.We take the message authentication as an example into a careful consideration.Then,we proposed a new message authentication scheme with the Advanced Encryption Standard as the encryption function and the new quantum Hash function as the authentication function.Firstly,the Advanced Encryption Standard algorithm is used to encrypt the result of the initial message cascading the corresponding Hash values,which ensures that the initial message can resist eavesdropping attack.Secondly,utilizing the new quantum Hash function with quantum walks can be much more secure than traditional classical Hash functions with keeping the common properties,such as one-wayness,resisting different collisions and easy implementation.Based on these two points,the message authentication scheme can be much more secure than previous ones.Finally,it is a new way to design the message authentication scheme,which provides a new thought for other researchers in the future.Our works will contribute to the study on the new encryption and authentication functions and the combination of quantum computing with traditional cryptology in the future.
基金Supported by the National Natural Science Foundation of China (No. 61173178, 61003247, 61070246) and the Fundamental Research Funds for the Central University (No. COJER1018002,cdjerl018003).
文摘A new algorithm for a novel hash function, based on chaotic tent map with changeable parameter, is proposed and analyzed. The one dimensional and piecewise tent map with changeable parameters decided by the position index of blocked messages is chosen, and blocked massages translated into ASCII code values are employed as the iteration time of the chaotic tent map. The final 128-bit hash value is generated by logical XOR operation on intermediate hash values. Theoretical analysis and computer simulation indicate that the proposed algorithm can satisfy the performance requirements of hash function.
文摘Message integrity is found to prove the transfer information of patient in health care monitoring system on the human body in order to collect and communicate the human personal data. Wireless body area network (WBAN) applications are the fast growing technology trend but security and privacy are still largely ignored, since they are hard to achieve given the limited computation and energy resources available at sensor node level. In this paper, we propose simple hash based message authentication and integrity code algorithm for wireless sensor networks. We test the proposed algorithm in MATLAB on path loss model around the human body in two scenarios and compare the result before and after enhancement and show how sensors are connected with each other to prove the message integrity in monitoring health environment.
基金This work was supported by the National Natural Science Foundation of China(No.61862054)Applied Basic Research Project of Qinghai Province(No.2019-ZJ-7066).
文摘Sorting the Tibetan language quickly and accurately requires first identifying the component elements that make up Tibetan syllables and then sorting by the priority of the component.Based on the study of Tibetan text structure,grammatical rules and syllable structure,we present a structurebased Tibetan syllable recognition method that uses syllable structure instead of grammar.This method avoids complicated Tibetan grammar and recognizes the components of Tibetan syllables simply and quickly.On the basis of identifying the components of Tibetan syllables,a Tibetan syllable sorting algorithm that conforms to the language sorting rules is proposed.The core of the Tibetan syllable sorting algorithm is a hash function.Research has found that the sorting of all legal Tibetan syllables requires eight components of information.The hash function is based on this discovery and can be assigned corresponding weights according to different sorting verify the effectiveness of the Tibetan sorting algorithm,we established an experimental corpus using the Tibetan sorting standard document recognized by the majority of Tibetan users,namely the New Tibetan Orthographic Dictionary.Experiments show that this method produces results completely consistent with standard reference works,with an accuracy of 100%,and with minimal computational time.
基金Project supported by the National Natural Science Foundation of China (Grant No. U0735004)the Natural Science Foundation of Guangdong Province,China (Grant No. 05006593)
文摘Based on the spatiotemporal chaotic system, a novel algorithm for constructing a one-way hash function is proposed and analysed. The message is divided into fixed length blocks. Each message block is processed by the hash compression function in parallel. The hash compression is constructed based on the spatiotemporal chaos. In each message block, the ASCII code and its position in the whole message block chain constitute the initial conditions and the key of the hash compression function. The final hash value is generated by further compressing the mixed result of all the hash compression vulues. Theoretic analyses and numerical simulations show that the proposed algorithm presents high sensitivity to the message and key, good statistical properties, and strong collision resistance.
文摘Hash functions are often used in the authentication of information security field. With the development of electronic commerce, the reliability of authentication is paid more and more attention to. This paper describes an N - LFSR which combined nonlinear S - box with the LF-SR, and substitutes it for CLS operator in hash function. The efficiency of new hash function is not drop and the ability of defence attack is strengthened.
基金supported by the Program for New Century Excellent Talents in University of China(No.NCET-06-0510)National Natural Science Founda-tion of China(No. 60874091)Six Projects Sponsoring Talent Summits of Jiangsu Province(No. SJ209006)
文摘In this paper,based on coupled network generated by chaotic logarithmic map,a novel algorithm for constructing hash functions is proposed,which can transform messages and can establish a mapping from the transformed messages to the coupled matrix of the network.The network model is carefully designed to ensure the network dynamics to be chaotic.Through the chaotic iterations of the network,quantization and exclusive-or (XOR) operations,the algorithm can construct hash value with arbitrary length.It is shown by simulations that the algorithm is extremely sensitive to the initial values and the coupled matrix of the network,and has excellent performance in one-way,confusion and diffusion,and collision resistance.
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region (Nos.2022D01C367 and 2022D01E33)Tianshan Talent Training Program (Nos.2023TSYCCX0037 and 2023TSYCQNTJ0020)National Natural Science Foundation of China (No.52267010).
文摘The design of a chaotic image encryption algorithm plays an essential role in enhancing information and communication security.The performance of such algorithms is intricately linked to the complexity of the chaotic sequence and the underlying encryption algorithm.To additionally enhance the complexity of hyperchaotic systems,this study presents a novel construction of a Five-Dimensional(5D)memristive hyperchaotic system through the introduction of the flux-controlled memristor model.The system's dynamic characteristics are examined through various analytical methods,including phase portraits,bifurcation diagrams,and Lyapunov exponent spectra.Accordingly,the sequences produced by the hyperchaotic system,which passed the National Institute of Standards and Technology(NIST)test,are employed to inform the creation of a novelty image encryption technique that combines hash function,Deoxyribonucleic Acid(DNA)encoding,logistic,and Two-Dimensional Hyperchaotic Map(2D-SFHM).It improves the sensitivity of key and plaintext images to image encryption,expands the algorithm key space,and increases the complexity of the encryption algorithm.Experimental findings and analysis validate the exceptional encryption capabilities of the novel algorithm.The algorithm exhibits a considerable key space 2512,and the ciphertext image demonstrates an information entropy of 7.9994,with inter-pixel correlation approaching zero,etc.,showcasing its resilience against different types of attacks on images.
基金Supported by the National Natural Science Foundation of China under Grant No. 60573032.
文摘In this paper, we present a fast attack algorithm to find two-block collision of hash function MD5. The algorithm is based on the two-block collision differential path of MD5 that was presented by Wang et al. in the Conference EUROCRYPT 2005. We found that the derived conditions for the desired collision differential path were not sufficient to guarantee the path to hold and that some conditions could be modified to enlarge the collision set. By using technique of small range searching and omitting the computing steps to check the characteristics in the attack algorithm, we can speed up the attack of MD5 efficiently. Compared with the Advanced Message Modification technique presented by Wang et al., the small range searching technique can correct 4 more conditions for the first iteration differential and 3 more conditions for the second iteration differential, thus improving the probability and the complexity to find collisions. The whole attack on the MD5 can be accomplished within 5 hours using a PC with Pentium4 1.70GHz CPU.
基金the National Natural Science Foundation of China(Grant No.90304009) the“973 Project”(Grant No.G19990358).
文摘Abstract In this paper, we give a fast attack against hash function HAVAL-128. HAVAL was presented by Y. L. Zheng et al. at Auscrypto'92. It can be processed in 3, 4 or 5 passes, and produces 128, 160, 192, or 224-bit fingerprint. We break the HAVAL with 128-bit fingerprint. The conclusion is that, given any 1024-bit message ra, we just make some modifications about m, and the modified message ra can collide with another message m only with probability 1/2^7, where m = m + △m, in which △m is a fixed difference selected in advance. In addition, two collision examples for HAVAL-128 are given in this paper.
基金supported by the National Basic Research Program of China (2015CB453000)
文摘Research on existing radio frequency identification(RFID) authentication protocols security risks, poor performance and other problems, a RFID security authentication protocol based on dynamic identification(ID) and Key value renewal is proposed. Meanwhile, the security problems based on Hash function RFID security authentication protocol in recent years have been also sorted and analyzed. Then a security model to design and analyze RFID protocols is built. By using the computational complexity, its correctness and security have been proved. Compared with the safety performance, storage overhead, computational overhead and other aspects of other protocols, the protocol for RFID has more efficient performance and ability to withstand various attacks. And the C# programming language is used to simulate the authentication process on the visual studio platform, which verifies the feasibility of the protocol.