Design of image Hash functions based on fluid dynamics model

The chain-like structure is used in most known Hash functions, which is not suitable for digital images. A new structure is adopted to design an image hash function based on the HPP model, a model originally aiming to simulate fluid flows, and impressive for its simplicity, 2D structure, and its ability to support parallel computing. In order to fulfill security requirements of a cryptographic hash function, the HPP model is generalized by combining the original model with a nonlinear substitution operation. Computer simulations and theoretical analyses demonstrate that this generalized model possesses satisfactory properties of randomness and sensitivity for hash functions.