Challenge-response based ACK message authentication

Although ACK (acknowledgement) should be short since it simply notifies a successful receipt, the actual size of ACK packets increases because of a message header or security options. Especially, in wireless sensor networks where efficiency is the highest priority due to the limited sensor resources, the size of ACK may be reduced by omitting some header fields or security options. However, this pursuit of efficiency can cause security vulnerability such as a faked ACK. In turn, the ACK cannot achieve the original purpose, i.e. to provide reliable communication, any more. Therefore, proposed is a novel ACK message authentication method based on a challenge-response authentication, which can achieve efficiency and security at the same time.