Security enhancement of MD5 hashed passwords by using the unused bits of TCP header

Abstract

When a password is encrypted by a hash algorithm the resultant is called hashed password. In a server client based communication system such as Yahoo Messenger, AIM, passwords of clients are hashed by MD5 and passed to the server for authentication. This type of transmission is always a subject of interception by the hackers. These hashed passwords are passed through the Internet as a data packet. TCP header is a most common part of the data packet. In a TCP header there are six reserved bits which remains always unused. In this paper we propose a new approach to enhance the security of hashed passwords by using the six reserved bits of a TCP header. Here we encrypt the hashed password by a random key using simple mathematical function. The information needed to decrypt the encrypted hashed password is carried by the six bits of TCP header.