Date Added: Dec 2012
According to the recent development, the authors look forward to further widespread use of wireless networks soon. Thus one of the issues that they face to them is shortage of spectrum. Cognitive Radio Networks (CRNs) are an appropriate way to overcome this deficiency and also CRNs increase productivity and efficiency of spectrum. The crucial assumption is that secondary user should not interfere with primary user, therefore when primary user does not use of spectrum, usage permission of this spectrum is given to authorized secondary user. So there must be a secure way for CRNs authentication and it must be able to deal with the attacks in CRNs authentication.