  This paper investigates and analyzes the dynamics of the two-dimensional
Duffing map. Multistability behavior has been observed from the system
numerically. Such behavior, especially the coexistence of chaotic and periodic
attractors, is undesirable in the applications of chaos-based cryptography.
Therefore, we design and implement a Sine-Cosine chaotification technique to
enhance chaos in the multistable regions. Furthermore, this paper proposes a
new image encryption algorithm to examine the performance of the generalized
Duffing map in cryptography applications. Simulation results and security
analysis reveal that the proposed algorithm can effectively encrypt and decrypt
several image types with a high level of security.
