Kad encryption algorithm

摘要

Kad is the most popular P2P file sharing system. Previous works only focus on the Kad network security or misuse. In this paper, we study the Kad transport layer's encryption and decryption algorithm. We find that Kad's encryption is a symmetric encryption. The KadID or IP address is the key. Researching Kad encryption algorithm could provides a reference for other P2P network security design. And it helps ISP identify and block Kad traffic. We put our codes on sourceforge. The experiment shows that our program could decrypt the cipher text correctly.