To solve the issue that it is difficult to monitor the content on the KAD network because of occult of KAD message, a novel monitoring approach was proposed to obtain the content by intercepting the interactive message for a specified node on the network. First of all, the HashID for a keyword in the message of a supervised node was extracted by using ID mapping method. Secondly, a lightweight method of reverse conversion algorithm was adopted to obtain the corresponding value for a specified HashID, which can further judge the threat level for the node. Finally, the experiment was deployed on the KAD network constructed by eMule system. When ten nodes in 0X10 zone were selected as targets, the above approach was adopted to intercept the quest and publish massages that send to supervised nodes, and the semantic content for messages is obtained successfully. The result of the experiment demonstrated the necessity for network supervision, as well as the feasibility of the approach.
