The novel bilateral – Diffusion image encryption algorithm with dynamical compound chaos

Chaos may be degenerated because of the finite precision effect, hence the new compound two-dimensional chaotic function is presented by exploiting two one-dimensional chaotic functions which are switched randomly. A new chaotic sequence generator is designed by the compound chaos which is proved by Devaney's definition of chaos. The properties of dynamical compound chaotic functions and LFSR are also proved rigorously. A novel bilateral-diffusion image encryption algorithm is proposed based on dynamical compound chaotic function and LFSR, which can produce more avalanche effect and more large key space. The entropy analysis, differential analysis, statistical analysis, cipher random analysis, and cipher sensitivity analysis are introduced to test the security of new scheme. Many experiment results show that the novel image encryption method passes SP 800-22 and DIEHARD standard tests and solves the problem of short cycle and low precision of one-dimensional chaotic function.

► A new dynamical compound chaotic function by exploiting two one-dimensional chaotic functions is proposed which are switched randomly.
► In order to produce lager key space, the dynamical properties of compound chaos and LFSR mixing are also proved rigorously.
► A novel bilateral-diffusion image encryption algorithm is proposed for more avalanche effect.
► The experiments show that the novel encryption algorithm solves the problem of short cycle and low precision of one-dimensional chaotic function.