Improving the Key Agreement Protocol Security Based on Hadamard Matrices

In this paper, the security of key agreement protocol based on Sylvester Hadamard matrices proposed by Chang-hui Choe and Moon Ho Lee has been improved. Applying new changes, the weakness of their protocol was introduced and its security was increased. In short, new symmetric key agreement protocol will be suitable for insecure communication when two users want to share a common secret key with the low computing power.