运用GD-PBIBD编码的矢量空间数据数字指纹算法

针对矢量空间数据叛逆者追踪难及编码效率低的问题，本文提出了一种运用GD-PBIBD码的指纹算法。首先运用GD-PBIBD构造指纹编码，将待嵌入指纹序列运用Logistic映射置乱，通过D-P算法提取矢量空间数据的特征点，对特征点实施DFT变换得到相位系数和幅度系数；然后运用QIM方法将指纹嵌入DFT变换域的幅度系数上；最后应用DFT逆变换得到含指纹的矢量空间数据。试验选取部分中国路网数据和某区域绿地数据，运用该算法嵌入指纹后，对其进行线性和非线性模拟攻击，成功提取指纹序列，利用汉明距离追踪出合谋者。该算法编码构造简单，在码长一定的情况下，较BIBD码可容纳更多的用户，效率高；算法抗单用户指纹攻击及多重攻击的稳健性较好，也能够抵抗多用户最小值和最大最小值攻击，追踪到所有叛逆者，可用于矢量空间数据版权保护，为矢量空间数据叛逆者追踪提供依据。

Digital fingerprint algorithm for vector spatial data using GD-PBIBD coding

Aiming at the difficulty of tracking traitors and low coding efficiency about fingerprint for vector map data, a fingerprint algorithm using GD-PBIBD code is proposed in this paper. Firstly, the fingerprint codes are generated by using the GD-PBIBD, also the fingerprint is shuffled by using the Logistic map before embedding. Then, the feature points of the vector map data are extracted by using the D-P algorithm, and the phase coefficients and amplitude coefficients are obtained by performing DFT transformation on the feature points. The QIM method is used to embed the fingerprint into the amplitude coefficient of the DFT transform domain, and the DFT inverse transform is implemented to obtain the vector map data containing the fingerprint. The experiment selected some Chinese road network and a certain area data in green space. After the fingerprint was embedded in the algorithm, linear and nonlinear simulation attacks were carried out. The fingerprint sequence was successfully extracted and the collaborators were tracked by Hamming distance. The algorithm has a simple coding structure. When the code length is fixed, it can accommodate more users than the BIBD code, and the efficiency is high. The algorithm is robust against single-user fingerprint attacks and multiple attacks, and can resist multi-user minimum and the maximum and minimum attacks, which track all traitors, can be used for vector map data copyright protection, provide a basis for vector space data traitor tracking.