.基于时间间隔的扩频流水印技术

将基于时间间隔的数据流调制方法和扩频通信原理相结合，提出基于时间间隔的扩频流水印技术，对于不同的待嵌水印位使用不同的正交伪噪声码进行扩展，通过调制包到达时间的统计特征将扩展水印信息嵌入到随机选择的时间间隔中。理论分析和实验结果表明，该技术可有效进行多流追踪，并能抵御多流和均方自相关攻击。

Interval-based spread spectrum watermarking scheme for tracing network flows

By combining interval-based watermarking flow modulation approach with spread spectrum communication principle, this paper proposed an interval-based spread spectrum watermarking (IBSSW) scheme for efficiently and simultaneously tracing multiple network traffic, which utilized multiple orthogonal pseudo-noise codes to spread different watermark bits and embeded them into randomly selected intervals by modulating the statistical characteristic of packets arriving time. Statistical analysis and empirical results indicate that IBSSW scheme, robust against multi-flow and mean-square autocorrelation attacks, can effectively trace multiple network flows.