Novel Sequence Number Based Secure Authentication Scheme for Wireless LANs

Authentication per frame is an implicit necessity for security in wireless local area networks(WLANs). We propose a novel per frame secure authentication scheme which provides authentication to data frames in WLANs. The scheme involves no cryptographic overheads for authentication of frames.It utilizes the sequence number of the frame along with the authentication stream generators for authentication.Hence, it requires no extra bits or messages for the authentication purpose and also no change in the existing frame format is required. The scheme provides authentication by modifying the sequence number of the frame at the sender, and that the modification is verified at the receiver. The modified sequence number is protected by using the XOR operation with a random number selected from the random stream. The authentication is lightweight due to the fact that it requires only trivial arithmetic operations like the subtraction and XOR operation.