中文摘要：

基于二维码的数字水印算法主要通过微调二维码的图形结构实现水印嵌入，隐蔽性较差，要求二维码图像具有较高的信息容量，而且不适合以电子形式保存。针对这些问题，提出一种适用于快速响应矩阵码的脆弱水印算法。在最不重要位替换嵌入算法的基础上引入矩阵编码，以此减少需要修改的最不重要位的位数，因而能够在增强水印隐蔽性的同时，有效地提高水印信息的嵌入效率。理论和实验分析表明，水印的隐蔽性不再受到快速响应矩阵码容量的影响，水印信息的大小也可以根据快速响应矩阵码的容量适当调节。用新方法嵌入水印的二维码图像适合以电子形式保存，并且能够广泛地应用于终端设备对电子票证的防伪验证。

英文摘要：

Digital image watermarking algorithm based on micro structural adjustment theory is widely used in 2D code. Since the invisibility of this watermark is poor, it requires a high capacity 2D code as carrier, and the 2D code with this watermark is not suitable for preservation as electronic document. Considering these problems, a fragile wa- termarking algorithm for QR Code is proposed. It combines least significant bit algorithm with matrix encoding to improve both the invisibility and embedding efficiency of watermark by reducing the num of least significant bit that need to be modified. Theoretical analyses and experiment show that the invisibility of watermark is no longer restrained by QR Code capacity, and the size of watermark can be suitable adjusted according to the carrier. 2D code with this new watermark can be preserved as electronic document and used as e-ticket for mobile.