A chaos-based keyed hash function for secure protocol and messege authentication in mobile ad hoc wireless networks

The design of communication protocols in the Mobile Ad hoc Networks (MANET) is challenging due to limited wireless transmission ranges of node mobility, limited power resources, and limited physical security. The advantages of MANET include simple and fast deployment, robustness, adaptive and self-organizing networks. Nonetheless, routing protocols are important operations for communication among wireless devices. Assuring secure routing protocols is challenging since MANET wireless networks are highly vulnerable to security attacks. Most traditional routing protocols and message authentication designs do not address security, and are mainly based on a mutual trust relationship among nodes. This paper therefore proposes a new chaos-based keyed hash function that can be used for communication protocols in MANET. The proposed chaotic map realizes an absolute-value nonlinearity, which offers robust chaos over wide parameter spaces, i.e. high degree of randomness through chaoticity measurements using Lyapunov exponent. The proposed keyed hash function structure is compact through the use of a single stage chaos-based topology. Hash function operations involve an initial stage when the chaotic map accepts input message and initial conditions, and a hashing stage where alterable-length hash values are generated iteratively. Hashing performances are evaluated in terms of original message condition changes, statistical analyses, and collision analyses. Results of hashing performances show that the mean changed probabilities are very close to 50%, and the mean changed bit number is also close to a half of hash value lengths. The proposed keyed hash function enhances the collision resistance, comparing to typical MD5 and SHA1, and is faster than other complicated chaos-based approaches.