Information Encryption using a Fisher-Schroedinger Model
Systems Research Corporation
Last modified: March 31, 2006
The process of probability density reconstruction from incomplete constraints (physical observables) is attacked within the framework of a Fisher game. The undetermined Lagrange multipliers are accurately obtained by employing a modified game corollary. In a practical application of the reconstruction model, a novel principle is given for encrypting a given code (covert in-formation) in a host statistical distribution. Information encryption is achieved through unitary projections of the code onto the null space of the under-determined eigensystem of the host statistical distribution. This is described by a time independent Schrödinger wave-like equation. This SWE contains an empirical pseudo-potential defined by undetermined Lagrange multipliers. A secret key to the covert information is found by exploiting the extreme sensitivity of the eigensystem of the statistical system to perturbations. The case of multiple keys (key ring strategy) is treated. The model is demonstrated to seamlessly switch from symmetric to asymmetric cryptography. Unique features of the encryption model that capture critical aspects of both cryptography and steganography are highlighted. Favorable comparisons with an equivalent maximum entropy formulation are made. Numerical examples of the reconstructed probability densities and code exemplify the efficacy of the model.