This paper reports a workin progress in the design of secure GIS systems. We need such designs when sensitive GIS data needs to be communicated over public networks. The ubiquity of public networks can lead to compromising sensitivity of data during data exchanges in response to a query. Cryptographic methods are designed independent of the relative importance of data, or its semantic content. The paper argues in favour of using spatial characteristics of GIS data to obtain an additional layer of security provided by using morphic manipulation of spatial objects. We discuss two families of morphic manipulation algorithms. While the first one achieves benign morphic alterations, the second family of algorithms offers enhanced morphic alterations with very extensive data-hiding potential. The paper limits its scope to two dimensional map data.