Geographic data are used on a variety of computing devices for many different applications including navigation, tracking, location planning, and marketing. The prevalence of geographic data makes it possible to envision new useful applications. In this paper, we propose using geographic data as a medium for secret communication, or steganography. We develop a method called StegoGIS for hiding messages in geographic coordinates in the well-known binary of fast-moving objects and transmitting them secretly. We show that discovering this secret communication is practically impossible for third parties. We also show that a large amount of secret data can be transmitted this way, and that the receiver can easily extract the hidden message. We argue that StegoGIS offers a novel and practical secret communication method with minimal overhead.common media files such as images [3,4], torrent files [5], text [6], geographical objects [7], or network packets [8].Geographical objects are composed of raster and vector data. Whereas raster data are based on a tessellation of image cells, vector data are based on vertices and paths. They can be categorized into three geometrical elements [9], which are points, lines, and polygons. Vector data are formed by spatial data, or in other words a sequence of coordinates describing the geographical locations of map objects, attribution data, and additional data. Vector data represent real-world features within a geographic information system (GIS) environment. GIS is used for processing geographical data as well as storing both the geometry and the attributes of these data.The rapid development of the Internet makes it easy to exchange information via networks. In particular, emerging web-based applications make information available to both public and private clients. In addition, web services are developed to support interoperable machine-to-machine interaction over a network. Based on web