A New Keyed Hash Function Based on Compounded Chaotic Maps

In this paper, we firstly construct a new chaotic map by compounding a couple of chaotic maps and, using specific mathematical tools (i.e., Lyapunov exponent), we prove its sensitivity to the initial conditions and the underlying chaotic behavior. Secondly, using this chaotic map, we propose a new chaotic keyed hash function which involves each byte of the message in calculation of the chaotic map initial point and the compounded maps control parameters. Corroborating this method with the proven sensitivity of the used chaotic map, we obtain an avalanche effect in the hashing process and the guarantee that all the bits of the message will be related to the hash value. Moreover, the exhaustive numerical simulations show that the proposed hash function has very good confusion and diffusion capabilities, strong collision resistance, high level of security and good speed, being suitable for applications regarding data integrity or authentication, such as ciphers or blockchain applications.