3D medical data security protection

• A novel encryption method for 3D biomedical objects is introduced.
• It is based on the use of cellular automata, boolean functions and discretized chaotic maps.
• The protocol involves two phases that produce confusion and diffusion.
• The encryption method directly acts on the 3D structure of the object defined by voxels.

A novel encryption protocol for 3D biomedical objects is introduced in this work. This method consists of two phases which are iteratively applied: the confusion phase and the diffusion phase. In the confusion phase the position of the voxels are permuted by means of a discretized chaotic map, whereas in the diffusion phase the value of each voxel is changed. The diffusion phase is divided into two sub phases: in the first one a memory reversible 3D cellular automata is applied using the 3D object as the initial conditions, and in the second sub phase, a discrete dynamical system with delay defined by a non-linear boolean function is applied to the output of the evolution of the cellular automaton. The protocol is shown to be secure against the most important cryptanalytic attacks.The impact and novelty of this method lies on directly ciphering the 3D objects and considering these objects as the aggregation of voxels. Moreover, this allows to design a new and efficient encryption algorithm which is the generalization of those methods to encrypt digital images that are based on the iteration of a confusion and a diffusion phase.The use of cellular automata and boolean transition rules in the diffusion phase opens new possibilities for the use of expert and intelligence systems in cryptography since cellular automata can be used and inference machines.