基于Barker码可靠网络流水印研究与实现

Research and implementation on robust network flow watermarking scheme based on Barker code

针对当前网络流水印技术存在的水印容量小、时间复杂度高问题,提出了一种基于Barker码的可靠网络流水印方法。该方法选择具有同步特性的Barker码作为PN码,通过扩频操作,将原始水印信息变为扩频信息序列,保证该序列具有自同步特性。通过主动调整网络流内数据包时间间隔IPD的大小来表示该信息序列,以完成原始水印信息在网络流内的嵌入过程。接收方在获取网络流的IPD值后,通过解扩操作即可恢复出该水印信息。实验结果表明,与其他方法相比,该法不仅能够明显提高网络流的水印容量,还能有效降低水印嵌入和提取过程的时间。

In order to solve the small watermark capacity and high time complexity problem of current network flow techniques,a robust network flow watermarking scheme based on Barker code（RFWBC）is proposed.Firstly,RFWBC chooses Barker code which owns self-synchronization feature as Pseudo-Noise（PN）code.With this Barker code,the original watermark can be spread into Spreading Bit Sequence（SBS）through spreading spectrum operation,so the SBS also has self-synchronization feature.After that,RFWBC actively adjusts the value of Inter Packet Delay（IPD）in a network flow to indicate the SBS,through which the original watermark can be embedded into this network flow.Finally,when the receiver captures this network flow and obtains all IPDs of it,the original watermark can be recovered by despreading spectrum operation.The experimental results show that,compared with other existing methods,RFWBC can not only increases the watermark capacity of one network flow greatly,but also reduce time cost of watermark embedding and recovering process effectively.