Distributed hash tables (DHTs) are a very interesting research topic in the area of P2P overlay networks; such networks are becoming very popular in applications like file sharing. The purpose of the Distributed Hash Table is providing the way to search the resources (especially files) within a P2P network. A DHT protocol typically provides a single function to the P2P application: provide a key and find the node (or may be nodes) which is liable for such key [1][3]. All other functions (such as actually retrieving the resource or storing the resource on the node responsible for it) are provided by higher layers of the P2P application. In such paper our target is to find the security issues and resolve them on existing routing protocols of such networks. The Chord [4] (a DHT protocol) is chosen as the target protocol for various reasons it will be covered in this paper.