基于透明加密的文件保密技术研究

最近几年互联网以惊人的速度发展着,现在几乎家家户户都有电脑。人们写东西,不管是邮件还是公司要用的文档,不再是手写,电脑或手机上字一打,通过网络传输给所要给的人,既快捷又方便。但是随之而来的问题就是怎样保证电子文档的安全保密。通常的手段是给文档加密,但是一般都是要户主手动加密,很麻烦,而且有时候还会忘记密码。有时可能会给户主带来严重的损失。比如某个经理要和客户谈合同,但是在这之前电脑被锁住了,不能及时把重要合同拿出来。所以现在比较热门的技术就是透明加密的文件保密技术,它可以在你操作文档的时候自动加密解密而你却不曾知晓,不会干扰到你正常操作。本文主要通过对常见泄密方法的分析,来研究透明加密系统总体设计。     

基于微过滤驱动的文件访问控制系统

采用微过滤模型设计的文件监控系统,可以实现文件访问的实时处理,拒绝非法文件操作的执行,限制用户操作某些特别重要的文件,提高Windows文件系统的安全性。     

协同认知模型数据加密和解密方法

将数据加密和解密的基本原理与协同认知模型的基本原理有机地结合起来,研究了协同认知模型数据加密和解密方法.协同认知模型数据加密和解密方法是一种简单而非常安全可靠的数据加密和解密方法.     

一种基于C语言的加密解密软件探讨

本文主要对信息加密技术中的置换方法和其加密解密思想进行详细介绍,对文件中的字符信息采用置换法进行加密,给出一个完整的加密解密软件,其详细的设计方法和步骤也相应给出,使用C语言对这一切加以实现。该软件,在信息传输和储存上都较高的安全性,可以有效防止被非法分子破解。     

基于小波水印的数字图像加密和解密

本文基于小波变换数字水印技术,提出了以水印类型、多项式形式和嵌入强度因子f作为加密密钥的图像加密方式。随水印嵌入强度因子f增大,水印加密图像的峰值信噪比PSNR迅速减小,原始图像逐渐被水印覆盖、隐藏。在掌握密钥前提下,利用小波逆运算可有效地将已经被完全覆盖的原始图像还原。     

1．3K服务器链路加解密板的数据采集与发送

本文分析了1．3K服务器链路加解密板的数据采集与数据发送,并给出了硬件设计以及软件设计。     

一种基于文件系统的在线数据迁移技术

介绍一种基于文件系统过滤驱动的在线数据迁移技术的架构、实现和难点解决方案。     

一个简单的自解密文件加密软件的制作

网上的文件加密程序很多,像最著名的winrar,winzip等。它们的实现算法相当复杂。同时还有一些简单的加密程序,有的操作虽然简单,却需要配套解密程序;或者是操作繁琐。     

具有字符过滤功能的包过滤防火墙的设计研究

一、绪论传统的包过滤防火墙系统主要是包过滤规则以IP信息包为基础,对IP源地址、IP目标地址、封装协议(TCP/UDP)、端口号等进行筛选。只有符合访问条件的数据包才被转发,其它包被丢弃。其功能设计主要是为在IP层和传输层上进行过滤的,而内容过滤在传统的包过滤防火墙上是难     

南工大研发新材料为信息加解密技术添"法宝"

正南京工业大学黄维院士率领先进材料研究院IAM团队开发出一种全新的信息加解密技术,以"光"作为信息载体,发掘运用磷光金属配合物的"特殊"性能,使得信息传输更为安全。据悉,该技术发现为国际首创。IAM团队的研究中巧妙地运用磷光金属配合物的长寿命发光优势,再结合时间分辨成像技术,使得原本只具备信息记录功能的光学信息存储,增加了信息保护功能。黄维说:"像磷光金属配合物这样的多刺激智能响应光电功能材料,今后可以广泛地应用在     

Multiple-image encryption scheme with a single-pixel detector

Abstract

A multiple-image encryption (MIE) scheme with a single-pixel detector has been proposed according to the principle of ghost imaging. In this scheme, each of the spatially coherent laser beams is modified by a set of phase-mask keys and illuminates on a secret image. All of the transmitted lights are recorded together by a single-pixel (bucket) detector to obtain a ciphertext, but anyone of the secret images can be decrypted from the ciphertext independently without any mutually overlapped despite some noise in them. The MIE scheme will bring convenience for data storage and transmission, especially in the case that different secret images need to be distributed to different authorized users, because the ciphertext is a real-valued function and this scheme can effectively avoid the secret images being extracted mutually. The basic principle of the MIE scheme is described theoretically and verified by computer simulations. Finally, the feasibility, robustness and encryption capacity are also tested numerically.     

Multiple images encryption method via spiral phase mask rotations under a JTC system

A method of multiple-image encryption via spiral phase mask rotations based on the joint transform correlator encryption system was proposed. Multiple images can be encrypted into one ciphertext through this approach. When decrypted the ciphertext, we have no need to produce too many key masks, only need rotate the key mask to the angle corresponding to the plaintext. The system also has good resistance to occlusion attack and differential attack. Computer simulations initially verified the correctness of this method, and the experimental results also confirmed its validity further.     

一种面向信息系统集成的双向安全认证方法研究

随着计算机网络技术的发展和信息化的普及,系统集成的重要程度日益提升,而信息安全则是集成过程中必须考虑的重点因素之一。本文提出了一种面向信息系统集成的双向安全认证方法,并对其关键步骤与核心算法做了详细阐述,该方法在一定程度上为系统集成过程中的身份认证环节提供了安全保障。     

Optical image encryption based on compressive sensing and chaos in the fractional Fourier domain

We propose a novel image encryption algorithm based on compressive sensing (CS) and chaos in the fractional Fourier domain. The original image is dimensionality reduction measured using CS. The measured values are then encrypted using chaotic-based double-random-phase encoding technique in the fractional Fourier transform domain. The measurement matrix and the random-phase masks used in the encryption process are formed from pseudo-random sequences generated by the chaotic map. In this proposed algorithm, the final result is compressed and encrypted. The proposed cryptosystem decreases the volume of data to be transmitted and simplifies the keys for distribution simultaneously. Numerical experiments verify the validity and security of the proposed algorithm.     

基于动态可变参数的复合混沌系统的语音加密算法研究

利用混沌理论,基于Hénon映射和Logistic映射设计了一个复合混沌系统,并证明了其具有更好的初值敏感性。对产生的混沌二值序列进行美国国家标准与技术研究所(National Institute of Standard and Technology,NIST)随机数测试,分析得出该序列具有较好的随机性,可用于加密。依此设计了一个语音加密算法,实现了语音信号的加/解密功能。仿真分析表明,该混沌语音加密算法具有较高的安全性,能产生足够的密钥空间,有较强的保密性能。     

Image compression and encryption scheme with hyper-chaotic system and mean error control

Based on a hyper-chaotic system, an image compression and encryption scheme is presented by adopting mean error control to improve the quantization compression performance of the discrete cosine transform (DCT) coefficients. The transform coefficients of DCT forming a structure similar to the sub-band can be classified and encoded. Then the image is scanned with Zigzag operation in different directions to achieve sufficiently scrambled effects. The cyclic shift matrix for image encryption is generated by the hyper-chaotic system. The four initial inputs for generating the cyclic shift matrix serve as the key. Simulation results demonstrate the security and the effectiveness of the proposed image compression and encryption scheme.     

Image encryption combining multiple generating sequences controlled fractional DCT with dependent scrambling and diffusion

Based on the fractional discrete cosine transform with multiple generating sequences (MGSFrDCT) and the dependent scrambling and diffusion (DSD), an image encryption algorithm is proposed, in which the multiple-generating sequences greatly enlarge the key space of the encryption system. The real-valued output of MGSFrDCT is beneficial to storage, display and transmission of the cipher-text. During the stage of confusion and diffusion, the locations and values of all MGSFrDCT transformed coefficients change due to DSD, and the initial values and fractional orders of encryption system depend not only on the cipher keys but also on the plain-image due to introduction of a disturbance factor, which allows the encryption system to resist the known-plaintext and chosen-plaintext attacks. Experimental results demonstrate that the proposed encryption algorithm is feasible, effective and secure and able to resist common classical attacks.     

一种以AOTF为核心的农药荧光检测系统

提出了一种将 AOTF 技术用于农药含量检测的荧光光谱系统。该系统分别采用以α-Quartz,TeO2 晶体作为声光介质的激发和发射色散元件 AOTF,以高压短弧氙灯为激发光源,利用光纤探测并传输荧光,由数据采集卡进行数据接收和 A/D 转换。该系统通过声光调制产生单色光,由超声射频的变化实现光谱扫描,没有机械调谐部件,故波长切换快、结构简单。西维因农药的荧光特性测量结果表明,系统的荧光波长范围为 500-750nm, 光谱分辨率为 10nm。当激发光波长为320nm,荧光波长为 647nm,西维因溶液浓度为 0.0-120.0μg/L 时,系统具有较好的线性关系,线性相关系数 r 为 0.9991。它可用于对粮食作物中的农药残留的检测和荧光光谱分析。     

Robust envelope-constrained filter with orthonormal bases and semi-definite and semi-infinite programming

In this paper, the equivalence relation between a semi-infinite quadratically constrained convex quadratic programming problem and a combined semi-definite and semi-infinite programming problem is considered. Then, an efficient and reliable discretization algorithm for solving a general class of combined semi-definite and semi-infinite programming problems is developed. Both the continuous-time envelope-constrained optimal equalization filter and the corresponding robust envelope-constrained filter for a communication channel are solved by using the proposed algorithm. This research was partially supported by the Research Committee of The Hong Kong Polytechnic University and the National Natural Science Foundation of China (Grant numbers: 60574073 and 10471142).     

基于Kriging模型和无迹卡尔曼滤波的转向架构架模型修正

为提高转向架构架模型的修正效率和实时性,提出了一种基于Kriging模型和无迹卡尔曼滤波的模型修正方法.首先,对构架进行模态分析,引入信息熵确定模态阶数来优选频响函数频率区间.其次,构造Kriging模型,将频响函数经过小波变换并提取第4层低频系数作为Kriging模型输出,并通过改进的灰狼算法(grey wolf o...