In recent years, the nearest neighbor search （NNS） problem has been widely used in various interesting applications. Locality-sensitive hashing （LSH）, a popular algorithm for the approximate nearest neighbor probl...In recent years, the nearest neighbor search （NNS） problem has been widely used in various interesting applications. Locality-sensitive hashing （LSH）, a popular algorithm for the approximate nearest neighbor problem, is proved to be an efficient method to solve the NNS problem in the high-dimensional and large-scale databases. Based on the scheme of p-stable LSH, this paper introduces a novel improvement algorithm called randomness-based locality-sensitive hashing （RLSH） based on p-stable LSH. Our proposed algorithm modifies the query strategy that it randomly selects a certain hash table to project the query point instead of mapping the query point into all hash tables in the period of the nearest neighbor query and reconstructs the candidate points for finding the nearest neighbors. This improvement strategy ensures that RLSH spends less time searching for the nearest neighbors than the p-stable LSH algorithm to keep a high recall. Besides, this strategy is proved to promote the diversity of the candidate points even with fewer hash tables. Experiments are executed on the synthetic dataset and open dataset. The results show that our method can cost less time consumption and less space requirements than the p-stable LSH while balancing the same recall.展开更多
Steganography is a technique for hiding secret messages while sending and receiving communications through a cover item.From ancient times to the present,the security of secret or vital information has always been a s...Steganography is a technique for hiding secret messages while sending and receiving communications through a cover item.From ancient times to the present,the security of secret or vital information has always been a significant problem.The development of secure communication methods that keep recipient-only data transmissions secret has always been an area of interest.Therefore,several approaches,including steganography,have been developed by researchers over time to enable safe data transit.In this review,we have discussed image steganography based on Discrete Cosine Transform(DCT)algorithm,etc.We have also discussed image steganography based on multiple hashing algorithms like the Rivest–Shamir–Adleman(RSA)method,the Blowfish technique,and the hash-least significant bit(LSB)approach.In this review,a novel method of hiding information in images has been developed with minimal variance in image bits,making our method secure and effective.A cryptography mechanism was also used in this strategy.Before encoding the data and embedding it into a carry image,this review verifies that it has been encrypted.Usually,embedded text in photos conveys crucial signals about the content.This review employs hash table encryption on the message before hiding it within the picture to provide a more secure method of data transport.If the message is ever intercepted by a third party,there are several ways to stop this operation.A second level of security process implementation involves encrypting and decrypting steganography images using different hashing algorithms.展开更多
In order to classify packet, we propose a novel IP classification based the non-collision hash and jumping table trie-tree (NHJTTT) algorithm, which is based on noncollision hash Trie-tree and Lakshman and Stiliadis p...In order to classify packet, we propose a novel IP classification based the non-collision hash and jumping table trie-tree (NHJTTT) algorithm, which is based on noncollision hash Trie-tree and Lakshman and Stiliadis proposing a 2-dimensional classification algorithm (LS algorithm). The core of algorithm consists of two parts: structure the non-collision hash function, which is constructed mainly based on destination/source port and protocol type field so that the hash function can avoid space explosion problem; introduce jumping table Trie-tree based LS algorithm in order to reduce time complexity. The test results show that the classification rate of NHJTTT algorithm is up to 1 million packets per second and the maximum memory consumed is 9 MB for 10 000 rules. Key words IP classification - lookup algorithm - trie-tree - non-collision hash - jumping table CLC number TN 393.06 Foundation item: Supported by the Chongqing of Posts and Telecommunications Younger Teacher Fundation (A2003-03).Biography: SHANG Feng-jun (1972-), male, Ph.D. candidate, lecture, research direction: the smart instrument and network.展开更多
This In the past decade there has been an increasing need for designs to address the time and cost efficiency issues from various computer network applications such as general IP address lookup and specific network in...This In the past decade there has been an increasing need for designs to address the time and cost efficiency issues from various computer network applications such as general IP address lookup and specific network intrusion detection. Hashing techniques have been widely adopted for this purpose, among which XOR-operation-based hashing is one of most popular techniques due to its relatively small hash process delay. In most current commonly used XOR-hashing algorithms, each of the hash key bits is usually explicitly XORed only at most once in the hash process, which may limit the amount of potential randomness that can be introduced by the hashing process. In [1] a series of bit duplication techniques are proposed by systematically duplicating one row of key bits. This paper further looks into various ways in duplicating and reusing key bits to maximize randomness needed in the hashing process so as to enhance the overall performance further. Our simulation results show that, even with a slight increase in hardware requirement, a very significant reduction in the amount of hash collision can be obtained by the proposed technique.展开更多
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
With the rapid development of information technology, demand of network & information security has increased. People enjoy many benefits by virtue of information technology. At the same time network security has b...With the rapid development of information technology, demand of network & information security has increased. People enjoy many benefits by virtue of information technology. At the same time network security has become the important challenge, but network information security has become a top priority. In the field of authentication, dynamic password technology has gained users’ trust and favor because of its safety and ease of operation. Dynamic password, SHA (Secure Hash Algorithm) is widely used globally and acts as information security mechanism against potential threat. The cryptographic algorithm is an open research area, and development of these state-owned technology products helps secure encryption product and provides safeguard against threats. Dynamic password authentication technology is based on time synchronization, using the state-owned password algorithm. SM3 hash algorithm can meet the security needs of a variety of cryptographic applications for commercial cryptographic applications and verification of digital signatures, generation and verification of message authentication code. Dynamic password basically generates an unpredictable random numbers based on a combination of specialized algorithms. Each password can only be used once, and help provide high safety. Therefore, the dynamic password technology for network information security issues is of great significance. In our proposed algorithm, dynamic password is generated by SM3 Hash Algorithm using current time and the identity ID and it varies with time and changes randomly. Coupled with the SM3 hash algorithm security, dynamic password security properties can be further improved, thus it effectively improves network authentication security.展开更多
This paper introduces a novel trust-aware hybrid recommendation framework that combines Locality-Sensitive Hashing(LSH)with the trust information in social networks,aiming to provide efficient and effective recommenda...This paper introduces a novel trust-aware hybrid recommendation framework that combines Locality-Sensitive Hashing(LSH)with the trust information in social networks,aiming to provide efficient and effective recommendations.Unlike traditional recommender systems which often overlook the critical influence of user trust,our proposed approach infuses trust metrics to better approximate user preferences.The LSH,with its intrinsic advantage in handling high-dimensional data and computational efficiency,is applied to expedite the process of finding similar items or users.We innovatively adapt LSH to form trust-aware buckets,encapsulating both trust and similarity information.These enhancements mitigate the sparsity and scalability issues usually found in existing recommender systems.Experimental results on a real-world dataset confirm the superiority of our approach in terms of recommendation quality and computational performance.The paper further discusses potential applications and future directions of the trust-aware hybrid recommendation with LSH.展开更多
Given the rapid development of advanced information systems,microgrids(MGs)suffer from more potential attacks that affect their operational performance.Conventional distributed secondary control with a small,fixed sam...Given the rapid development of advanced information systems,microgrids(MGs)suffer from more potential attacks that affect their operational performance.Conventional distributed secondary control with a small,fixed sampling time period inevitably causes the wasteful use of communication resources.This paper proposes a self-triggered secondary control scheme under perturbations from false data injection(FDI)attacks.We designed a linear clock for each DG to trigger its controller at aperiodic and intermittent instants.Sub-sequently,a hash-based defense mechanism(HDM)is designed for detecting and eliminating malicious data infiltrated in the MGs.With the aid of HDM,a self-triggered control scheme achieves the secondary control objectives even in the presence of FDI attacks.Rigorous theoretical analyses and simulation results indicate that the introduced secondary control scheme significantly reduces communication costs and enhances the resilience of MGs under FDI attacks.展开更多
如何有效地对数据进行布局是大规模网络存储系统面临的重大挑战,需要一种能够自适应存储规模变化、公平有效的数据布局算法.提出的CCHDP(clustering-based and consistent hashing-aware data placement)算法将聚类算法与一致hash方法...如何有效地对数据进行布局是大规模网络存储系统面临的重大挑战,需要一种能够自适应存储规模变化、公平有效的数据布局算法.提出的CCHDP(clustering-based and consistent hashing-aware data placement)算法将聚类算法与一致hash方法相结合,引入少量的虚拟设备,极大地减少了存储空间.理论和实验证明,CCHDP算法可以按照设备的权重公平地分布数据,自适应存储设备的增加和删除,在存储规模发生变化时迁移最少的数据量,并且可以快速地定位数据,对存储空间的消耗较少.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61173143)the Special Public Sector Research Program of China(Grant No.GYHY201206030)the Deanship of Scientific Research at King Saud University for funding this work through research group No.RGP-VPP-264
文摘In recent years, the nearest neighbor search （NNS） problem has been widely used in various interesting applications. Locality-sensitive hashing （LSH）, a popular algorithm for the approximate nearest neighbor problem, is proved to be an efficient method to solve the NNS problem in the high-dimensional and large-scale databases. Based on the scheme of p-stable LSH, this paper introduces a novel improvement algorithm called randomness-based locality-sensitive hashing （RLSH） based on p-stable LSH. Our proposed algorithm modifies the query strategy that it randomly selects a certain hash table to project the query point instead of mapping the query point into all hash tables in the period of the nearest neighbor query and reconstructs the candidate points for finding the nearest neighbors. This improvement strategy ensures that RLSH spends less time searching for the nearest neighbors than the p-stable LSH algorithm to keep a high recall. Besides, this strategy is proved to promote the diversity of the candidate points even with fewer hash tables. Experiments are executed on the synthetic dataset and open dataset. The results show that our method can cost less time consumption and less space requirements than the p-stable LSH while balancing the same recall.
文摘Steganography is a technique for hiding secret messages while sending and receiving communications through a cover item.From ancient times to the present,the security of secret or vital information has always been a significant problem.The development of secure communication methods that keep recipient-only data transmissions secret has always been an area of interest.Therefore,several approaches,including steganography,have been developed by researchers over time to enable safe data transit.In this review,we have discussed image steganography based on Discrete Cosine Transform(DCT)algorithm,etc.We have also discussed image steganography based on multiple hashing algorithms like the Rivest–Shamir–Adleman(RSA)method,the Blowfish technique,and the hash-least significant bit(LSB)approach.In this review,a novel method of hiding information in images has been developed with minimal variance in image bits,making our method secure and effective.A cryptography mechanism was also used in this strategy.Before encoding the data and embedding it into a carry image,this review verifies that it has been encrypted.Usually,embedded text in photos conveys crucial signals about the content.This review employs hash table encryption on the message before hiding it within the picture to provide a more secure method of data transport.If the message is ever intercepted by a third party,there are several ways to stop this operation.A second level of security process implementation involves encrypting and decrypting steganography images using different hashing algorithms.
文摘In order to classify packet, we propose a novel IP classification based the non-collision hash and jumping table trie-tree (NHJTTT) algorithm, which is based on noncollision hash Trie-tree and Lakshman and Stiliadis proposing a 2-dimensional classification algorithm (LS algorithm). The core of algorithm consists of two parts: structure the non-collision hash function, which is constructed mainly based on destination/source port and protocol type field so that the hash function can avoid space explosion problem; introduce jumping table Trie-tree based LS algorithm in order to reduce time complexity. The test results show that the classification rate of NHJTTT algorithm is up to 1 million packets per second and the maximum memory consumed is 9 MB for 10 000 rules. Key words IP classification - lookup algorithm - trie-tree - non-collision hash - jumping table CLC number TN 393.06 Foundation item: Supported by the Chongqing of Posts and Telecommunications Younger Teacher Fundation (A2003-03).Biography: SHANG Feng-jun (1972-), male, Ph.D. candidate, lecture, research direction: the smart instrument and network.
文摘This In the past decade there has been an increasing need for designs to address the time and cost efficiency issues from various computer network applications such as general IP address lookup and specific network intrusion detection. Hashing techniques have been widely adopted for this purpose, among which XOR-operation-based hashing is one of most popular techniques due to its relatively small hash process delay. In most current commonly used XOR-hashing algorithms, each of the hash key bits is usually explicitly XORed only at most once in the hash process, which may limit the amount of potential randomness that can be introduced by the hashing process. In [1] a series of bit duplication techniques are proposed by systematically duplicating one row of key bits. This paper further looks into various ways in duplicating and reusing key bits to maximize randomness needed in the hashing process so as to enhance the overall performance further. Our simulation results show that, even with a slight increase in hardware requirement, a very significant reduction in the amount of hash collision can be obtained by the proposed technique.
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.
文摘With the rapid development of information technology, demand of network & information security has increased. People enjoy many benefits by virtue of information technology. At the same time network security has become the important challenge, but network information security has become a top priority. In the field of authentication, dynamic password technology has gained users’ trust and favor because of its safety and ease of operation. Dynamic password, SHA (Secure Hash Algorithm) is widely used globally and acts as information security mechanism against potential threat. The cryptographic algorithm is an open research area, and development of these state-owned technology products helps secure encryption product and provides safeguard against threats. Dynamic password authentication technology is based on time synchronization, using the state-owned password algorithm. SM3 hash algorithm can meet the security needs of a variety of cryptographic applications for commercial cryptographic applications and verification of digital signatures, generation and verification of message authentication code. Dynamic password basically generates an unpredictable random numbers based on a combination of specialized algorithms. Each password can only be used once, and help provide high safety. Therefore, the dynamic password technology for network information security issues is of great significance. In our proposed algorithm, dynamic password is generated by SM3 Hash Algorithm using current time and the identity ID and it varies with time and changes randomly. Coupled with the SM3 hash algorithm security, dynamic password security properties can be further improved, thus it effectively improves network authentication security.
文摘This paper introduces a novel trust-aware hybrid recommendation framework that combines Locality-Sensitive Hashing(LSH)with the trust information in social networks,aiming to provide efficient and effective recommendations.Unlike traditional recommender systems which often overlook the critical influence of user trust,our proposed approach infuses trust metrics to better approximate user preferences.The LSH,with its intrinsic advantage in handling high-dimensional data and computational efficiency,is applied to expedite the process of finding similar items or users.We innovatively adapt LSH to form trust-aware buckets,encapsulating both trust and similarity information.These enhancements mitigate the sparsity and scalability issues usually found in existing recommender systems.Experimental results on a real-world dataset confirm the superiority of our approach in terms of recommendation quality and computational performance.The paper further discusses potential applications and future directions of the trust-aware hybrid recommendation with LSH.
基金supported by Hainan Provincial Natural Science Foundation of China(No.524RC532)Research Startup Funding from Hainan Institute of Zhejiang University(No.0210-6602-A12202)Project of Sanya Yazhou Bay Science and Technology City(No.SKJC-2022-PTDX-009/010/011).
文摘Given the rapid development of advanced information systems,microgrids(MGs)suffer from more potential attacks that affect their operational performance.Conventional distributed secondary control with a small,fixed sampling time period inevitably causes the wasteful use of communication resources.This paper proposes a self-triggered secondary control scheme under perturbations from false data injection(FDI)attacks.We designed a linear clock for each DG to trigger its controller at aperiodic and intermittent instants.Sub-sequently,a hash-based defense mechanism(HDM)is designed for detecting and eliminating malicious data infiltrated in the MGs.With the aid of HDM,a self-triggered control scheme achieves the secondary control objectives even in the presence of FDI attacks.Rigorous theoretical analyses and simulation results indicate that the introduced secondary control scheme significantly reduces communication costs and enhances the resilience of MGs under FDI attacks.
文摘如何有效地对数据进行布局是大规模网络存储系统面临的重大挑战,需要一种能够自适应存储规模变化、公平有效的数据布局算法.提出的CCHDP(clustering-based and consistent hashing-aware data placement)算法将聚类算法与一致hash方法相结合,引入少量的虚拟设备,极大地减少了存储空间.理论和实验证明,CCHDP算法可以按照设备的权重公平地分布数据,自适应存储设备的增加和删除,在存储规模发生变化时迁移最少的数据量,并且可以快速地定位数据,对存储空间的消耗较少.
