Collision-based flexible image encryption algorithm

This paper presents a novel image encryption algorithm, which is flexible to encrypt digital images with different precisions. The algorithm is construct from three collision-based dynamical systems: Hardy–Pomeau–Pazzis (HPP) model, rotary element (RE) model and billiard-particle model. Both the HPP and RE model are efficient and can support parallel computing; the billiard-particle is an excellent model for round key expansion. These models are revised to best suits image encryption. Analyses and simulations demonstrate that the proposed algorithm has satisfactory properties of randomness and sensitivity.

► HPP and rotary element models are efficient and support parallel computing.
► Billiard-particle model fits for round key expansion.
► Three dynamical systems are revised to design image encryption algorithm.
► New algorithm is fast, parallel and is flexible to various precisions.