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Underwater Pulse Waveform Recognition Based on Hash Aggregate Discriminant Network
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作者 WANG Fangchen ZHONG Guoqiang WANG Liang 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第3期654-660,共7页
Underwater pulse waveform recognition is an important method for underwater object detection.Most existing works focus on the application of traditional pattern recognition methods,which ignore the time-and space-vary... Underwater pulse waveform recognition is an important method for underwater object detection.Most existing works focus on the application of traditional pattern recognition methods,which ignore the time-and space-varying characteristics in sound propagation channels and cannot easily extract valuable waveform features.Sound propagation channels in seawater are time-and space-varying convolutional channels.In the extraction of the waveform features of underwater acoustic signals,the effect of high-accuracy underwater acoustic signal recognition is identified by eliminating the influence of time-and space-varying convolutional channels to the greatest extent possible.We propose a hash aggregate discriminative network(HADN),which combines hash learning and deep learning to minimize the time-and space-varying effects on convolutional channels and adaptively learns effective underwater waveform features to achieve high-accuracy underwater pulse waveform recognition.In the extraction of the hash features of acoustic signals,a discrete constraint between clusters within a hash feature class is introduced.This constraint can ensure that the influence of convolutional channels on hash features is minimized.In addition,we design a new loss function called aggregate discriminative loss(AD-loss).The use of AD-loss and softmax-loss can increase the discriminativeness of the learned hash features.Experimental results show that on pool and ocean datasets,which were collected in pools and oceans,respectively,by using acoustic collectors,the proposed HADN performs better than other comparative models in terms of accuracy and mAP. 展开更多
关键词 convolutional channel hash aggregate discriminative network aggregate discriminant loss waveform recognition
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基于双向Hash链的无线传感网络通信节点自愈算法
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作者 李晓薇 李翔宇 《传感技术学报》 CSCD 北大核心 2024年第12期2119-2124,共6页
无线传感网络中节点数量突增,增大了出现失效节点的概率,会影响数据传输效率,导致次级节点出现失效现象,为此提出基于双向hash链的无线传感网络通信节点自愈算法。分析无线传感网络节点流量过载现象,构建节点失效裁决模型,找出网络中失... 无线传感网络中节点数量突增,增大了出现失效节点的概率,会影响数据传输效率,导致次级节点出现失效现象,为此提出基于双向hash链的无线传感网络通信节点自愈算法。分析无线传感网络节点流量过载现象,构建节点失效裁决模型,找出网络中失效节点;利用质心算法确定失效节点具体位置,将双向hash链和节点失效裁决模型结合起来,实现对失效节点的自愈修复。构建WSN拓扑结构,对所提方法展开仿真测试,对比结果表明所提方法的节点拓扑移动距离平均值为63.5 m,网络流量出口带宽值平均值为583 Mbyte/s,节点自愈耗时平均值为14.2 s,证明该方法具有较高的自愈效率,保证了失效节点自愈效果最优、自愈能力最强。 展开更多
关键词 网络通信 通信节点自愈 双向hsh链 节点失效 质心算法 流量过载
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One-way hash function based on hyper-chaotic cellular neural network 被引量:1
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作者 杨群亭 高铁杠 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第7期2388-2393,共6页
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
关键词 one-way hash function HYPER-CHAOS cellular neural network Runge Kutta formula
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Constructing Hash Function Based on Coupled Network Generated by Logarithmic Map
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作者 SONG Yu-rong JIANG Guo-ping 《南京邮电大学学报(自然科学版)》 2010年第1期6-10,共5页
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
关键词 计算机网络 应用程序 网络安全 网络协议
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An Online Malicious Spam Email Detection System Using Resource Allocating Network with Locality Sensitive Hashing 被引量:1
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作者 Siti-Hajar-Aminah Ali Seiichi Ozawa +2 位作者 Junji Nakazato Tao Ban Jumpei Shimamura 《Journal of Intelligent Learning Systems and Applications》 2015年第2期42-57,共16页
In this paper, we propose a new online system that can quickly detect malicious spam emails and adapt to the changes in the email contents and the Uniform Resource Locator (URL) links leading to malicious websites by ... In this paper, we propose a new online system that can quickly detect malicious spam emails and adapt to the changes in the email contents and the Uniform Resource Locator (URL) links leading to malicious websites by updating the system daily. We introduce an autonomous function for a server to generate training examples, in which double-bounce emails are automatically collected and their class labels are given by a crawler-type software to analyze the website maliciousness called SPIKE. In general, since spammers use botnets to spread numerous malicious emails within a short time, such distributed spam emails often have the same or similar contents. Therefore, it is not necessary for all spam emails to be learned. To adapt to new malicious campaigns quickly, only new types of spam emails should be selected for learning and this can be realized by introducing an active learning scheme into a classifier model. For this purpose, we adopt Resource Allocating Network with Locality Sensitive Hashing (RAN-LSH) as a classifier model with a data selection function. In RAN-LSH, the same or similar spam emails that have already been learned are quickly searched for a hash table in Locally Sensitive Hashing (LSH), in which the matched similar emails located in “well-learned” are discarded without being used as training data. To analyze email contents, we adopt the Bag of Words (BoW) approach and generate feature vectors whose attributes are transformed based on the normalized term frequency-inverse document frequency (TF-IDF). We use a data set of double-bounce spam emails collected at National Institute of Information and Communications Technology (NICT) in Japan from March 1st, 2013 until May 10th, 2013 to evaluate the performance of the proposed system. The results confirm that the proposed spam email detection system has capability of detecting with high detection rate. 展开更多
关键词 MALICIOUS SPAM EMAIL Detection System INCREMENTAL Learning Resource Allocating network LOCALITY Sensitive hashING
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Cross-Modal Hashing Retrieval Based on Deep Residual Network
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作者 Zhiyi Li Xiaomian Xu +1 位作者 Du Zhang Peng Zhang 《Computer Systems Science & Engineering》 SCIE EI 2021年第2期383-405,共23页
In the era of big data rich inWe Media,the single mode retrieval system has been unable to meet people’s demand for information retrieval.This paper proposes a new solution to the problem of feature extraction and un... In the era of big data rich inWe Media,the single mode retrieval system has been unable to meet people’s demand for information retrieval.This paper proposes a new solution to the problem of feature extraction and unified mapping of different modes:A Cross-Modal Hashing retrieval algorithm based on Deep Residual Network(CMHR-DRN).The model construction is divided into two stages:The first stage is the feature extraction of different modal data,including the use of Deep Residual Network(DRN)to extract the image features,using the method of combining TF-IDF with the full connection network to extract the text features,and the obtained image and text features used as the input of the second stage.In the second stage,the image and text features are mapped into Hash functions by supervised learning,and the image and text features are mapped to the common binary Hamming space.In the process of mapping,the distance measurement of the original distance measurement and the common feature space are kept unchanged as far as possible to improve the accuracy of Cross-Modal Retrieval.In training the model,adaptive moment estimation(Adam)is used to calculate the adaptive learning rate of each parameter,and the stochastic gradient descent(SGD)is calculated to obtain the minimum loss function.The whole training process is completed on Caffe deep learning framework.Experiments show that the proposed algorithm CMHR-DRN based on Deep Residual Network has better retrieval performance and stronger advantages than other Cross-Modal algorithms CMFH,CMDN and CMSSH. 展开更多
关键词 Deep residual network cross-modal retrieval hashING cross-modal hashing retrieval based on deep residual network
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Hash function construction using weighted complex dynamical networks
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作者 宋玉蓉 蒋国平 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第4期172-177,共6页
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
关键词 hash function weighted complex dynamical networks chaotic map CRYPTOGRAPHY
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Data-Centric Routing Mechanism Using Hash-Value in Wireless Sensor Network
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作者 Xiaomin Zhao Keji Mao +1 位作者 Shaohua Cai Qingzhang Chen 《Wireless Sensor Network》 2010年第9期710-717,共8页
Traditional routing protocols as TCP/IP can not be directly used in WSN, so special data-centric routing protocols must be established. The raised data-centric routing protocols can not identify the sensor nodes, beca... Traditional routing protocols as TCP/IP can not be directly used in WSN, so special data-centric routing protocols must be established. The raised data-centric routing protocols can not identify the sensor nodes, because many nodes work under a monitoring task, and the source of data is not so important some times. The sensor node in the network can not judge weather data is come from the some sink node. What’s more, the traditional method use IP to identify sensors in Internet is not suitable for WSN. In this paper, we propose a new naming scheme to identify sensor nodes, which based on a description of sensor node, the description of a sensor node is hashed to a hash value to identify this sensor. The different description generates different identifier. Different from IP schema, this identifier is something about the information of the sensor node. In the above naming scheme, we propose a new data-centric routing mechanism. Finally, the simulation of the routing mechanism is carried out on MATLAB. The result shows our routing mechanism’s predominate increase when network size increase. 展开更多
关键词 Wireless SENSOR network Routing hash Value SENSOR IDENTIFIER
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Lung Nodule Image Retrieval Based on Convolutional Neural Networks and Hashing
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作者 Yan Qiang Xiaolan Yang +2 位作者 Juanjuan Zhao Qiang Cui Xiaoping Du 《Journal of Beijing Institute of Technology》 EI CAS 2019年第1期17-26,共10页
Lung medical image retrieval based on content similarity plays an important role in computer-aided diagnosis of lung cancer.In recent years,binary hashing has become a hot topic in this field due to its compressed sto... Lung medical image retrieval based on content similarity plays an important role in computer-aided diagnosis of lung cancer.In recent years,binary hashing has become a hot topic in this field due to its compressed storage and fast query speed.Traditional hashing methods often rely on highdimensional features based hand-crafted methods,which might not be optimally compatible with lung nodule images.Also,different hashing bits contribute to the image retrieval differently,and therefore treating the hashing bits equally affects the retrieval accuracy.Hence,an image retrieval method of lung nodule images is proposed with the basis on convolutional neural networks and hashing.First,apre-trained and fine-tuned convolutional neural network is employed to learn multilevel semantic features of the lung nodules.Principal components analysis is utilized to remove redundant information and preserve informative semantic features of the lung nodules.Second,the proposed method relies on nine sign labels of lung nodules for the training set,and the semantic feature is combined to construct hashing functions.Finally,returned lung nodule images can be easily ranked with the query-adaptive search method based on weighted Hamming distance.Extensive experiments and evaluations on the dataset demonstrate that the proposed method can significantly improve the expression ability of lung nodule images,which further validates the effectiveness of the proposed method. 展开更多
关键词 LUNG NODULE image retrieval convolutional neural networks INFORMATIVE SEMANTIC features hashING
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Homomorphic Hashing Verification for Wireless Sensor Networks Rateless Codes Over-the-Air Programming
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作者 Hao He Weidong Yi +1 位作者 Ming Li Yongrui Chen 《Journal of Beijing Institute of Technology》 EI CAS 2019年第1期109-118,共10页
The homomorphic hash algorithm(HHA)is introduced to help on-the-fly verify the vireless sensor network(WSN)over-the-air programming(OAP)data based on rateless codes.The receiver calculates the hash value of a group of... The homomorphic hash algorithm(HHA)is introduced to help on-the-fly verify the vireless sensor network(WSN)over-the-air programming(OAP)data based on rateless codes.The receiver calculates the hash value of a group of data by homomorphic hash function,and then it compares the hash value with the receiving message digest.Because the feedback channel is deliberately removed during the distribution process,the rateless codes are often vulnerable when they face security issues such as packets contamination or attack.This method prevents contaminating or attack on rateless codes and reduces the potential risks of decoding failure.Compared with the SHA1 and MD5,HHA,which has a much shorter message digest,will deliver more data.The simulation results show that to transmit and verify the same amount of OAP data,HHA method sends 17.9% to 23.1%fewer packets than MD5 and SHA1 under different packet loss rates. 展开更多
关键词 wireless sensor network(WSN) over-the-air PROGRAMMING rateless CODES homomorphic hashING security
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基于GAN的语义对齐网络半监督跨模态哈希方法
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作者 刘华咏 朱婷 《计算机科学》 北大核心 2025年第6期159-166,共8页
监督方法在跨模态检索中已有不少成果,是比较热门的方法。然而,这类方法过于依赖标记的数据,没有充分利用无标签数据所包含的丰富信息。为了解决这一问题,人们开始研究无监督方法,但是仅依靠未标记数据的效果并不理想。对此,提出了基于... 监督方法在跨模态检索中已有不少成果,是比较热门的方法。然而,这类方法过于依赖标记的数据,没有充分利用无标签数据所包含的丰富信息。为了解决这一问题,人们开始研究无监督方法,但是仅依靠未标记数据的效果并不理想。对此,提出了基于GAN的语义对齐网络半监督跨模态哈希方法(GAN-SASCH)。该模型基于生成对抗网络,结合了语义对齐的概念。生成对抗网络分为两个模块,分别是生成器和判别器,生成器学习拟合未标记数据的相关性分布并生成虚假的数据样本,判别器则用于判断数据对样本是来自数据集还是生成器。通过这两个模块之间展开极大极小的对抗博弈游戏,不断提升生成对抗网络的性能。语义对齐能充分利用不同模态之间的相互作用和对称性,统一不同模态的相似性信息,有效地指导哈希代码的学习过程。除此之外,还引入了自适应学习优化参数以提升模型性能。在NUS-WIDE和MIRFLICKR25K数据集上,对比了所提方法与9种相关前沿方法,使用MAP与PR图两种评价指标验证了所提方法的有效性。 展开更多
关键词 跨模态哈希 生成对抗网络 语义对齐 半监督 自适应学习
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基于变色龙哈希加密的无线传感网数据聚合隐私保护
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作者 庞峰 窦立君 《现代电子技术》 北大核心 2025年第21期72-76,共5页
为避免未授权用户获取敏感信息,提升数据聚合隐私保护效果,文中提出一种基于变色龙哈希加密的无线传感网数据聚合隐私保护方法。通过密钥生成算法、哈希算法与求逆算法,构建强变色龙哈希函数;依据强变色龙哈希函数内的公私钥,建立动态... 为避免未授权用户获取敏感信息,提升数据聚合隐私保护效果,文中提出一种基于变色龙哈希加密的无线传感网数据聚合隐私保护方法。通过密钥生成算法、哈希算法与求逆算法,构建强变色龙哈希函数;依据强变色龙哈希函数内的公私钥,建立动态变色龙认证树,防止数据聚合过程中敏感信息泄露给未经授权的第三方,提升数据聚合隐私保护效果;依据动态变色龙认证树,设计无线传感网数据聚合隐私保护协议,通过高级加密标准算法先加密基站上传的数据再采用聚合节点存储数据,完成数据聚合隐私保护。实验结果证明:该方法可有效加密基站上传的数据,完成无线传感网数据聚合隐私保护;在不同概率攻击下,该方法的数据完整性均较高,即数据聚合隐私保护效果较优,可有效避免未授权用户获取敏感信息,提升隐私保护效果。 展开更多
关键词 变色龙 哈希加密 无线传感网 数据聚合 隐私保护 认证树 高级加密 聚合节点
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移动边缘计算中的多层区块链网络数据防篡改方法研究
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作者 叶惠仙 《成都工业学院学报》 2025年第3期44-49,共6页
研究移动边缘计算中的多层区块链网络数据防篡改方法,有效弥补网络攻击漏洞,降低数据被篡改的风险。构建移动边缘计算中的多层区块链网络数据防篡改架构,边缘层的边缘节点采集边缘计算中产生的数据,发送到边缘区块链中进行存储;边缘区... 研究移动边缘计算中的多层区块链网络数据防篡改方法,有效弥补网络攻击漏洞,降低数据被篡改的风险。构建移动边缘计算中的多层区块链网络数据防篡改架构,边缘层的边缘节点采集边缘计算中产生的数据,发送到边缘区块链中进行存储;边缘区块链组合随机数与网络数据,结合哈希算法与不对称的公钥和私钥,对移动边缘计算中的多层区块链网络数据进行加密,并利用解密方式反向验证数据是否被篡改,阻止危险发生,保障数据私钥泄露后的数据防篡改;中间层中间节点定期将边缘区块链获取的安全数据包发布给中间区块链,并在认证层认证节点作用下完成移动边缘计算数据的安全保护。实验结果说明,所提方法可有效保障移动边缘计算中的多层区块链网络数据安全,避免数据被篡改,同时所提方法应用后数据被篡改次数很低,抗攻击性能强,数据存储无丢失,稳定性好。 展开更多
关键词 区块链 移动边缘计算 防篡改方法 哈希算法 网络数据 私钥加密
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无线通信网络密钥管理系统密文去重方法
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作者 白晓东 顾柄楠 +2 位作者 韩长飞 曹保聚 卢荣湖 《计算机时代》 2025年第4期15-19,共5页
无线通信网络密钥管理系统易受噪声影响,去重耗时较高。为提高密文数据去重效率和安全性,提出无线通信网络密钥管理系统密文去重方法。构建密文大摘要,完成密文数据上传逆向操作;基于哈希值验证下载权限,执行密文数据下载。基于相似词... 无线通信网络密钥管理系统易受噪声影响,去重耗时较高。为提高密文数据去重效率和安全性,提出无线通信网络密钥管理系统密文去重方法。构建密文大摘要,完成密文数据上传逆向操作;基于哈希值验证下载权限,执行密文数据下载。基于相似词结合深度学习提取密钥关联特征,实现密文去重。试验表明:该方法密文去重用时几乎不受信噪比影响,900 MB数据块耗时104.2 ms,幅值区间约为-10 V到10 V,有效提升了去重效率和安全性。 展开更多
关键词 无线通信网络 哈希值 信噪比 深度学习 密文去重
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物联网系统中网络编码混合加密方案 被引量:2
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作者 俞惠芳 郭欣 《信息安全研究》 北大核心 2025年第4期326-332,共7页
网络编码允许中间节点对收到的消息编码之后转发给下游节点,然而却存在着由于传播污染信息浪费大量网络资源等问题.为了解决这些问题,提出适用于物联网系统的网络编码混合加密方案(network coding hybrid encryption scheme,NCHES).NCHE... 网络编码允许中间节点对收到的消息编码之后转发给下游节点,然而却存在着由于传播污染信息浪费大量网络资源等问题.为了解决这些问题,提出适用于物联网系统的网络编码混合加密方案(network coding hybrid encryption scheme,NCHES).NCHES实现了任意长度消息的安全通信,同态哈希函数的使用防止了传输数据被污染.NCHES在数据通信过程中能保证较低的计算开销和较高的网络传输效率,而且能保证物联网系统中的数据安全. 展开更多
关键词 混合加密 安全传输 同态哈希函数 网络编码方案 无证书
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基于深度哈希的多模态临床数据相似病例检索
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作者 谢明朗 袁贞明 +1 位作者 施军平 田昕 《计算机系统应用》 2025年第5期173-184,共12页
随着电子健康档案(EHR)的普及,相似患者检索已成为支持辅助诊断和制定治疗计划等临床决策的重要任务.然而,EHR数据具有高维度、异构性且数量大的特点.为了有效整合多模态临床数据并实现高效检索,本文提出了一种基于深度哈希的多模态临... 随着电子健康档案(EHR)的普及,相似患者检索已成为支持辅助诊断和制定治疗计划等临床决策的重要任务.然而,EHR数据具有高维度、异构性且数量大的特点.为了有效整合多模态临床数据并实现高效检索,本文提出了一种基于深度哈希的多模态临床数据相似病例检索模型——MCDF.该模型根据不同模态数据的特性,将结构化文本数据、非结构化文本数据、图像数据分别使用多层感知机(multi-layer perceptron,MLP)模型、BioBERT、BioMedCLIP进行特征提取,并通过自注意力机制模块进行特征融合.利用三元组损失函数引导模型直接生成能够有效代表样本的哈希码,通过哈希码快速比对实现样本检索,不仅能提高检索的准确性,还能显著提升检索效率.本文基于公开数据集MIMIC-III,采用归一化折扣累计收益均值(MNDCG)和均值平均精度(MAP)作为评价指标,将MCDF模型与传统哈希方法(如spectral hashing)和先进哈希方法(如deep hashing network)进行比较.实验结果显示,MCDF模型的表现优于所有基线模型,验证了本文提出模型的优越性. 展开更多
关键词 相似患者检索 多模态数据融合 深度哈希网络
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基于Hash函数的TIN拓扑关系重建 被引量:4
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作者 潘胜玲 刘学军 +1 位作者 黄雄 唐秀娟 《地理与地理信息科学》 CSCD 北大核心 2006年第2期21-24,29,共5页
STL模型是CAD、景观造型器等图形处理软件中常用的三角形网络文件格式,该文件由于不带有三角形的拓扑关系,使其不便与GIS中的地形模型(如TIN)进行叠置分析等操作。提出一种基于Hash函数的STL模型的三角形拓扑重建算法,讨论Hash函数设计... STL模型是CAD、景观造型器等图形处理软件中常用的三角形网络文件格式,该文件由于不带有三角形的拓扑关系,使其不便与GIS中的地形模型(如TIN)进行叠置分析等操作。提出一种基于Hash函数的STL模型的三角形拓扑重建算法,讨论Hash函数设计和评价,给出基于Hash函数的TIN拓扑重建算法和拓扑检查方法,并通过实例对该算法进行验证。 展开更多
关键词 hash函数 TIN 拓扑关系
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基于Hash函数的抗攻击无线认证方案 被引量:6
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作者 史庭俊 马建峰 《系统工程与电子技术》 EI CSCD 北大核心 2006年第1期122-126,共5页
针对无线网络的特点,给出了一种高效的抗攻击认证方案。此方案通过建立服务器与客户机之间的提问(puzzle)机制,有效均衡了服务器与整个网络间资源的不对称。协议的主要思想是,当服务器的资源使用率达到一定阈值时,服务器触发puzzle机制... 针对无线网络的特点,给出了一种高效的抗攻击认证方案。此方案通过建立服务器与客户机之间的提问(puzzle)机制,有效均衡了服务器与整个网络间资源的不对称。协议的主要思想是,当服务器的资源使用率达到一定阈值时,服务器触发puzzle机制,即采用Hash函数产生并向客户机提交puzzle,当客户机正确求解puzzle后方可获得服务器相应的认证服务。在此过程中,服务器产生puzzle与客户机求解puzzle所需的系统代价相比要小得多。对协议的分析表明,协议安全可靠,能够有效抵御DoS等多种类型的攻击,并且具有计算负荷小、附加通信量低、协商次数少和自适应抗DoS攻击等特点。 展开更多
关键词 DOS攻击 无线网络 认证 hash函数
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基于Hash函数的WSN密钥分配方案 被引量:2
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作者 方旺盛 张涛 陈康 《计算机工程》 CAS CSCD 北大核心 2010年第11期161-163,共3页
针对经典随机密钥预分配方案存储和通信开销大、安全性不足的问题,提出一种基于Hash函数的无线传感器网络密钥预分配方案。采用Hash函数单向运算提高密钥安全性,通过单次广播过程分配密钥法降低通信开销。仿真结果表明,该方案可降低存... 针对经典随机密钥预分配方案存储和通信开销大、安全性不足的问题,提出一种基于Hash函数的无线传感器网络密钥预分配方案。采用Hash函数单向运算提高密钥安全性,通过单次广播过程分配密钥法降低通信开销。仿真结果表明,该方案可降低存储开销,提高节点抗俘获攻击能力,且通信开销从O(2N)降至O(N)。 展开更多
关键词 hash函数 无线传感器网络 密钥预分配
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基于改进的Vision Transformer深度哈希图像检索 被引量:1
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作者 杨梦雅 赵琰 薛亮 《陕西科技大学学报》 北大核心 2025年第4期183-191,共9页
针对基于卷积神经网络的深度哈希方法不能很好捕捉全局图像信息和数据集中难易样本、正负样本对不平衡的问题,提出一种基于改进的Vision Transformer深度哈希算法(CMTH).首先,在Transformer编码网络前利用卷积神经网络提取深度局部特征... 针对基于卷积神经网络的深度哈希方法不能很好捕捉全局图像信息和数据集中难易样本、正负样本对不平衡的问题,提出一种基于改进的Vision Transformer深度哈希算法(CMTH).首先,在Transformer编码网络前利用卷积神经网络提取深度局部特征,降低维度并保持较高的图像分辨率.其次,改进的Vision Transformer网络使用轻量级多头互注意模块,提取高维深度全局特征的同时降低计算复杂度.最后,提出新的损失框架,设计标准焦点损失调整难样本在数据集中的权重,并构建一种新的哈希损失,以减少难易样本不平衡和正负样本对不平衡的影响.在CIFAR-10和NUS-WIDE上与基于Vision Transformer的深度哈希次优算法相比,在四种不同比特下均值平均精度分别平均提高了2.35%和3.75%. 展开更多
关键词 深度哈希 卷积神经网络 视觉注意力 图像检索
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