基于区块链的数字版权认证模型

针对现有区块链版权系统在区块存储空间有限和版权验证依赖数据库数据的问题,设计一种文本作品的区块链版权认证模型.通过扩展区块结构将作品内容完整存储在区块链中,解决了数据库存储作品内容易被更改的问题.作品版权验证不再依赖数据库作品内容,依靠区块链的不可篡改性和非对称加密技术的唯一性,保证了作品版权验证过程的安全性.理论分析...     

A robust software watermarking for copyright protection

This paper advocates protecting software copyright through hiding watermarks in various data structures used by the code, e.g., B+-trees, R-trees, linked lists, etc. Prior proposals hide the watermarks in dummy data structures, e.g., linked lists and graphs that are created, solely for this reason, during the execution of the hosting software. This makes them vulnerable to subtractive attacks, because the attacker can remove the dummy data structures without altering the functionality or the semantic of the software program. We argue that hiding watermarks in one or more data structures that are used by the program would make the watermark more robust because disturbing the watermark would affect the semantic and the functionality of the underlying software. The challenge is that the insertion of the watermark should have a minimal effect on the operations and performance of the data structure.This paper proposes a novel method for watermarking R-tree data structure and its variants. The proposed watermarking technique does not change the values of the stored data objects. It takes advantage of the redundancy in the order of entries inside the R-tree nodes. Entries are arranged relative to a “secret” initial order, known only to the software owner, using a technique based on a numbering system that uses variable radix with factorial base. The addition of the watermark in the R-tree data structure does not affect the performance nor does it increase the size of the R-tree. The paper provides a detailed security analysis and performance evaluation to show that the embedded watermarks are robust and can withstand various types of attacks.     

基于矢量量化的数字水印综述

基于矢量量化的数字水印作为新出现的水印技术，对数字产品的版权保护起着非常重要的作用。本文对基于矢量量化的数字水印算法做了综述，介绍了现有的各种水印算法，分析了各自的特点，并指出下一步的研究方向。     

Robust multi bit and high quality audio watermarking using pseudo-random sequences

A robust multi bit and high quality audio watermarking technique in time domain is proposed in this paper. Watermarking is a technique used to label digital media by hiding copyright or other information into the underlying data. The watermark must be imperceptible and undetectable by the user and should be robust to various types of distortion. To enhance the robustness and taper-resistance of the embedded watermark, in this paper a multi bit technique is employed. Instead of embedding one bit into an audio frame, multiple bits can be embedded into each audio sub-frame. For attackers, since they do not know the parameters, this significantly reduces the possibility of unauthorized bit detection and removal of watermark. In real-time watermarking applications, robustness is not the only factor that plays an important role. The other factor that plays a very an important role is computational complexity. In general, audio file is transmitted in compressed form. Real-time watermark embedding must take into account this compressed form, because first decompressing the data, adding a watermark and then recompressing the data is computationally too demanding. In this paper, we propose robust and low complexity audio watermarking algorithm. To evaluate the performance of the proposed audio watermarking algorithm, subjective and objective quality tests including bit error rate (BER) and signal-to-noise ratio (SNR) were conducted. Compared to traditional one bit embedding algorithm, the proposed algorithm gives highly recovery rate after attack by commonly used audio data manipulations, such as low pass filtering, requantization, resampling, and MP3 compression.     

A DCT-based ownership identification method with gray-level and colorful signatures

In this paper, we propose an ownership identification method based on discrete cosine transformation (DCT). The copyright owner can select a gray-level or colorful image to be an ownership statement, which is used as a claim to the ownership of his/her work. Unlike traditional watermarking schemes, the ownership statement is not embedded into the image to be protected. Instead, our method will construct an ownership share for the author according to the feature of the original image and the ownership statement. The feature map of the original image is composed of DC coefficients of different DCT blocks. When piracy happens, the author can show his ownership share to reveal the ownership statement to prove his/her copyright. Note that the size of the ownership statement is not restricted to being smaller than that of the host image. In addition, multiple ownership statements can be registered for a single image without destroying each other. The experimental results will show the robustness of our scheme against several common attacks. Finally, we will give some discussions and comparisons with other researchers’ study.     

彩色数字水印技术研究

本文对彩色水印技术进行了详细地研究，提出了一种双彩色数字水印方案，实验结果表明，该算法性能良好，对于一般的图像处理和JPEG压缩具有较好的鲁棒性。     

数字水印及其应用

数字水印是用信号处理的方法，在数字化的多媒体数据中嵌入的隐蔽标记，本文研究了数字水印的关键技术，探讨了数字水印在版权保护、电子交易，票据防伪等方面的应用，最后展望了数字水印的发展前景。     

基于混沌加密的DCT域图像水印算法

数字水印技术向多媒体作品中加入不易察觉但可以判定区分的秘密信息，从而起到保护数字作品的版权或完整性的作用。根据人眼视觉系统模型对图像感知的视觉掩蔽效应，提出了一种基于混沌序列加密的DCT域数字图像水印算法，并利用中间数据文件实现了水印的盲提取和检测。最后，实验说明了算法的有效性和稳健性。     

一种基于非对称水印的图像认证改进算法研究

提出一种基于非对称水印的图像认证改进算法,算法中将经过BCH编码和混沌序列调制的认证信息作为水印,利用所有者私钥嵌入图像DCT域,嵌入过程根据DCT块的可视噪声阈值(JND)控制,用户可以利用公钥从水印图像中提取认证信息,但无法从公钥中获取任何私钥信息,从而无法破坏或删除水印.实验结果表明:改进算法中水印图像的PSNR值相比原算法增大4.4dB,并且对常见的基于图像处理的攻击,鲁棒性大大提高.