System and method for compressing electronic data such as, for example topological data (altitude/depth) or geospatial data (latitude/longitude) with constrained loss of fidelity. With respect to altitude/depth data, the system and method allow for a mixture of shoreline and deep water to be thinned within the same mesh without appreciable loss of information in either region. System and method retain underlying grid values, opening RTIN functionality for any sphere where original grid positions must be preserved. System and method provide for encryption/decryption of electronic data.