The Worldwide Interoperability for Microwave Access (WIMAX /IEEE 802.16), is new technology basedon wireless metropolitan area network. Security of connections access in WIMAX /IEEE 802.16 iscomplete with respect to the Privacy Key Management (PKM) protocol. The protocol is responsible forproviding the secure distribution of keying data from Base Station (BS) to Subscriber Station (SS). In thispaper we provide the formal analysis of PKMv2 using Scyther tool to verify the security properties. Wefound that PKMv2 is vulnerable to replay, DoS, Man-in-the middle attacks. At last we have proposed asecure protocol (SPKM) to prevent the authorization protocol from such attacks.