Abstract: Watermark technology has been used for verifying the integrity and correctness of sensor collected data.However，most of the watermark technologies used in wireless sensor networks are not reversible.The embedded watermarks make some damage to the sensor collected data.In this paper，traditional reversible watermark algorithm based on difference expansion algorithm is introduced to wireless sensor network.Combined with characteristics of node collaboration work in wireless sensor network，This paper proposes a reversible watermark algorithm aiming to solve the data recovery problem in wireless sensor networks.Target on the sensors’ loosely organization problem and sensor’s weak defensiveness problem，the proposed algorithm splits the whole watermark into several segments and assigns the segments randomly to sensors，which enhance the ability to resist collusion attack.Meanwhile，a pair of synchronous random number generators are used for sensors and the sink to solve the data freshness distinguished problem.

Key words: wireless sensor network, reversible watermarking, multi-node negotiation

摘要： 数字水印技术已被用于保障传感器网络所采集数据的完整性与正确性，已有的无线传感器网络中的水印技术几乎都是不可逆的，因而嵌入的水印会对采集的数据具有一定的破坏。为此，将传统的基于差分扩展的可逆水印算法引入到无线传感器网络，并结合无线传感器网络节点协同工作的特点，将已有基于差分扩展的可逆水印算法发展为多节点协商可逆的数字水印算法。该算法针节点结构松散、自身防御能力弱等问题将整体水印分为一定数目的片段，并由各组节点进行随机化处理使所有的片段呈随机性分布，以增加共谋攻击的难度。同时在节点和终端间用一对同步的随机序列发生器解决了对数据的新鲜性鉴别的问题。

关键词: 无线传感器网络, 可逆水印, 多节点协商