基于自毁式数字水印的信息隐藏通信技术

目的为了提高信息隐藏通信技术的安全性,提出一种自毁式数字水印隐藏通信技术,即使非法者截获信息的载体也无法获得信息内容。方法将生成的含水印信息的图像分切成图像碎片以此破坏内嵌的水印信息,使水印信息无法从单个的图像碎片中提取,必须经过图像碎片拼接算法合成原始含水印图像后才能提取水印信息。结果通过实验仿真分析,对于大小为32×32像素的8×8个图像碎片,复原的含水印图像无任何图像碎片拼接错位,拼接平均耗时为1.59 s,因此能实现实时在线拼接复原并顺利提取出水印信息。结论从信息的嵌入到最后信息的提取都能顺利地隐藏信息的内容和信息的存在,信息传递过程中信息的安全性能好,因此,自毁式数字水印信息隐藏通信技术是一种可行性极高的信息隐藏通信技术。     

简论数字水印在企业信息化中的应用

信息隐藏是信息安全的核心技术之一,在信息安全中的地位举足轻重,因此,如何在企业信息化中有效地利用信息隐藏技术也变得越来越重要。而信息隐藏技术中的数字水印技术应用广泛,充分利用数字水印技术可以保证企业关键数据的安全,在企业信息化的发展过程中能起到巨大的推动作用。     

量子计算和量子信息理论研究取得进展

<正>量子计算和量子信息处理是人们利用物质的量子行为而设计的量子信息处理技术。量子算法显示现今金融系统和互联网所普遍采用的公钥保密算法并不是安全的,它可以被量子计算机容易的破解。同时量子信息技术也提供了建立在量子力学基本原理基础上的量子密码协约。     

数字水印技术及其在数字化多媒体版权保护中的应用

数字水印技术是种信息隐藏技术,它是为适应信息隐藏与跟踪需要而诞生的。自1993年以来,国内外开始并尝试一种新的信息安全的技术,即将机密资料隐藏到一般的文件中,然后再通过网络采传递。由于非法拦截者从网络上拦截下来的是伪装后的资料,它们看起来与一般非机密     

基于数字隐藏技术(DHT)的彩色图像自适应水印算法

本论文提出了一种新颖的彩色图像水印方案。研究发现与RGB颜色空间线性相关、分量无关的颜色空间对水印应用最适合。本水印方案对彩色图像的自适应是通过把PSNR值保持在一定的品质范围之内，同时调整水印强度参数来达到的。水印是盲水印，即只需要水印的生成和随机系数密钥，并不需要原始图像。实验结果显示了该方法对一些常见的图像处理攻击具有鲁棒性，水印检测结果准确，且算法的计算量合理。     

数字水印技术浅析

数字水印技术是数字文件产权保护的重要技术,本文主要介绍数字水印的分类、特征与数字水印嵌入算法的研究现状。     

浅谈信息隐藏技术

阐述信息隐藏技术的基本概念、分类及主要特征,并对信息隐藏的原理和方法进行分析,概括它的主要应用领域.     

基于PWM占空比的印刷量子点图像信息识读

目的 针对目前PQP点阵数据的识读算法准确率较低速度较慢的问题,为了加快该信息隐藏与印刷防伪方法的推广应用,文中设计一种基于PWM占空比判据的PQP快速识读算法。方法 首先对采集到的PQP图像在非校正条件下,利用脉冲宽度调制(PWM)和最小占空比寻优方法,估算其点阵图像的栅格角度,然后根据所求得的栅格角度参照PQP点阵图像,分别计算横纵2个方向的极大值序列,之后对该序列进行二次差分和自适应阈值判决以绘制PQP点阵数据识读栅格,最后以方形螺旋线指向顺序索引网格内各位置特征值来识读PQP点阵数据信息。结果 通过仿真和实验测试得出,当打印分辨率为600 dpi时,PQP图像信息的识读时间和误码率分别控制在0.5 s和±5%以内。结论 在非校正、无参考和盲同步信息等不确定条件下,实现了对PQP点阵图像的信息提取。     

基于神经网络的数字水印技术研究

利用神经网络刻画图像相关性这一特征,采用基于这种特征的BP网络嵌入脆弱水印算法,用于图像内容完整性保护的脆弱水印技术,提高水印的鲁棒性和灵活性,它相对于传统的数字签名技术更具优势。     

基于HVS的数字水印技术研究

本文对HVS技术以及数字水印技术进行了论述研究,并将其HVS技术应用与数字水印技术当中,仿真结果表明,水印具有良好的性能。     

Digital watermarking based on fractal image coding

Abstract

With advances in computer network and multimedia technology, digital media are rapidly proliferating, and thus the issue of copyright protection for electronic publishing is receiving great attention. To achieve the goal of copyright protection, the digital watermarks are used to identify the owner of a certain image, so as to prevent illegal copying. Digital watermarking is the technique that embeds an invisible signal including owner identification and copy control information into multimedia data such as audio, video, and images. A new digital watermark approach based on fractal image coding is proposed in this paper. We present a way to use the fractal code as a means of embedding a watermark into image. The proposed approach has been shown to be resistant to general attacks, like StirMark. Moreover, someone who owns the decryption key can simply extract the digital watermark from the watermarked image without resorting to the original image.     

Key ideas in quantum error correction

In this introductory article on the subject of quantum error correction and fault-tolerant quantum computation, we review three important ingredients that enter known constructions for fault-tolerant quantum computation, namely quantum codes, error discretization and transversal quantum gates. Taken together, they provide a ground on which the theory of quantum error correction can be developed and fault-tolerant quantum information protocols can be built.     

Digital angular-displacement transducer with iterative error correction

This article considers the design of digital amplitude and phase angular-displacement transducers (ADT) with rotating sine-cosine transformers as sensors. The precision of these devices is increased by using one of the most effective algorithmic methods, the method of iterative error correction, which has been developed by the authors within the framework of circuitry for ADT's. Translated from Izmeritel'naya Tekhnika, No. 5, pp. 15–17, May, 1995.     

Combined error correction techniques for quantum computing architectures

Abstract

Proposals for quantum computing devices are many and varied. They each have unique noise processes that make none of them fully reliable at this time. There are several error correction/avoidance techniques which are valuable for reducing or eliminating errors, but not one, alone, will serve as a panacea. One must therefore take advantage of the strength of each of these techniques so that we may extend the coherence times of the quantum systems and create more reliable computing devices. To this end we give a general strategy for using dynamical decoupling operations on encoded subspaces. These encodings may be of any form; of particular importance are decoherence-free subspaces and quantum error correction codes. We then give means for empirically determining an appropriate set of dynamical decoupling operations for a given experiment. Using these techniques, we then propose a comprehensive encoding solution to many of the problems of quantum computing proposals which use exchange-type interactions. This uses a decoherence-free subspace and an efficient set of dynamical decoupling operations. It also addresses the problem of controllability in solid-state quantum dot devices.     

一种新的自适应量化数字音频水印算法

文章中提出了一种新的自适应量化数字音频水印算法，该算法首先将视觉可辨的二值水印图像降维成一维水印序列，并对水印序列进行随机置乱与BCH纠错编码，再将原始数字音频信号划分成音频数据段，最后选择音频段进行快速傅立叶变换(FFT)，并依据人类听觉系统(HAS)模型自适应确定量化步长量化FFT系数嵌入水印信息。该算法提取水印信息时不需要原始数字音频信号。仿真结果表明：该自适应量化数字音频水印算法不仅具有较好的透明性，而且对诸如叠加噪声、有损压缩、低通滤波、重新采样等攻击均具有较好的鲁棒性。     

Research on digital watermarking for vector maps based on coding compression

提出了一种新的数字矢量地图信息隐藏方案.该方案通过建立动态编码压缩表缩减水印编码长度,达到提高水印容量的目的;同时将数字水印压缩码嵌入到地图属性文件的对象定义块内的冗余空间中,由于压缩信息都存储在结束符之后,使得任何地图编辑及浏览软件都无法阅读或显示嵌入冗余空间的水印信息.实验结果表明该隐藏方案鲁棒性强,具有突出的不可感知性,方案对地理精度零损伤,可抵抗剪切、旋转、投影等多种几何攻击.     

Digital image watermarking based on VSS in BTC domain

Abstract

An image watermarking model based on visual secret sharing (VSS) is proposed for protection of ownership. In the embedding phase, the watermark is first divided by VSS into two parts: a hiding watermark and a secret watermark. Then only the hiding watermark is embedded into the original image and the secret watermark is reserved for watermark extracting by the owner. In the extracting phase, the hiding watermark is extracted from the watermarked image first and then directly superimposed on the secret watermark to recover the watermark information.     

基于最优模型残差的指纹方向校正法

指纹的方向信息是指纹图像处理中非常重要的信息,指纹方向场的获取以及校正直接影响指纹自动识别的性能。本文提出了一种基于指纹方向场数学模型的方向校正方法,根据指纹中的奇异点性质和分布,建立起与对应指纹方向场的最优方向场模型;然后,根据模型与实际指纹方向场的残差对指纹方向进行校正。由于算法利用指纹整体的拓扑信息对指纹噪声方向进行校正,具有很强的抗干扰能力,较适合劣质指纹图像处理。     

Digital correction of A/D conversion error due to multiplexingdelay

A measurement channel which consists of a multiplexer, sample-and-hold circuit, and analog-to-digital (A/D) converter is studied. It is designed for the synchronous sampling and measurement of two or more voltage signals V₁(t), V ₂(t), . . ., but the finite time of A/D conversion (ΔT) makes it impossible to acquire consecutive samples closer in time than ΔT. This can become a source of measurement error if further processing of the measurement data is based on the assumption of ideal synchronism. It has been found that interpolation filters, developed from the Lagrange polynomial interpolation, are useful tools for solving the problem of correction. An illustrative example of their use is presented