## 6 Conclusions  
In this paper, the vulnerabilities of the HWMP protocol based on the different types of possible attacks against the protocol were explored. Based on a vulnerability analysis, the security requirements for HWMP were determined. The existing HWMP security protocols, CCMP, BIP, SHWMP, IBC-HWMP, ECDSA-HWMP and Watchdog-HWMP, were analyzed based on these security requirements. We determined that the existing security protocols do not provide sufficient security protection for the HWMP frames. As shown in our security analysis, CCMP and BIP can protect the HWMP frames from external attacks. In other words, the existing security protocol, as defined in the 802.11w standard, is sufficient to protect the HWMP frames from external attacks. Therefore, the real problem with respect to HWMP security is the possibility of internal attacks. Unfortunately, SHWMP provides insecure end-to-end authentication and integrity for broadcasting and unicasting messages. Additionally, SHWMP does not have any security schemes for PERR HWMP routing protocol frames, and it does not provide the authentication and integrity assurance of NMF from the source node to protect NMF modification attacks. In addition, an anti-replay scheme does not exist in SHWMP. IBC-HWMP and ECDSA-HWMP attempt to address the problem of internal attacks, but their protection against external attacks is highly flawed. These two schemes have no end-to-end and point-to-point integrity service for NMFs. IBC-HWMP does not explain how to protect RANN and PERR. This protocol does not provide the authentication and integrity assurance of non-mutable field from the source node for the intermediate nodes on the transmission path to protect non-mutable field modification attacks. In addition, an anti-replay scheme does not exist in this protocol. Because the two schemes use a digital signature on the broadcasting PREQ message, a significant number of message drops can occur if the signature verification cannot be processed at line speed. Watchdog-HWMP cannot detect illegal modification or creation in the non-mutable field, which is a major target for internal attacks. As the number of nodes increase, Watchdog-HWMP suffers much more performance degradation in terms of packet loss throughput. It is desirable to include the monitoring of message drop and non-mutable field change into watchdog processing. SHWMP, IBC-HWMP, or ECDSA-HWMP does not provide any permission level for an MP to declare itself as the root mesh STA. We conclude that CCMP/BIP should always be taken into consideration when developing a new security protocol for HWMP because it is very effective against external attacks. We have the following recommendations for the future development of the HWMP security protocol. First, end-to-end based integrity services for NMF must be provided. These services will prevent intermediate mesh STAs from modifying the sequence number or impersonating originator/target mesh STAs. Second, a permission level should also be implemented so that only authorized mesh STAs can designate themselves as the root mesh STA. Third, an efficient method to detect a fake path metric from any malicious mesh STAs should be implemented. One of the most difficult issues to address is mutable field forgery detection. Because a path metric in MF should be updated by intermediate mesh STAs as it propagates, it cannot be protected with end-to-end authentication and integrity services. Fourth, any security schemes for RANN and PERR must be implemented. We found that the existing security protocols for HWMP do not protect RANN and/or PERR messages. Fifth, the authentication and integrity assurance from the source node for the intermediate nodes on the transmission path should be implemented. The existing security protocols for HWMP do not provide this security service. This service is very important to protect NMF modification or forgery activities related with route disruption, route invasion, resource consumption, and node isolation attacks. Sixth, anti-replay schemes should be implemented.