Bong-Joo Jang

Perceptual encryption with compression for secure vector map data processing

With the rapidly rising interest in geographic information system (GIS) contents, a large volume of valuable map data has been unlawfully distributed by pirates. Therefore, the secure storage and transmission of classified national digital map datasets have been increasingly threatened. As the importance of secure, large-volume map datasets has increased, vector map security techniques that focus on secure network and data encryption have been studied. These techniques are required to ensure access control and prevent illegal copying of digital maps. This paper presents perceptual encryption on the vector compression domain for copy protection and access control of vector maps. Our algorithm compresses all vector data of polylines and polygons by lossless minimum coding object (MCO) units and perceptually encrypts using two processes using the mean points and directions of MCOs. The first process changes the position of vector data by randomly permuting the mean points of MCOs, the so-called position encryption. The second process changes the geographic shape by circularly encrypting the directions of vertices in MCOs by the XOR operator. Experimental results have verified that our algorithm can encrypt GIS digital maps effectively and simply and can also improve the compression ratio, unlike general data encryption techniques, and thus, our algorithm is very effective for a large volume of GIS datasets. We design a lossy/lossless compression and perceptual encryption algorithm for vector map.Our algorithm ensures access control and copyright protection of vector map.Each object is performed independently for random access about specified location.All objects are compressed as a unit of minimum coding object (MCO) units.All objects are perceptually encrypted using mean points and directions of MCO.

Progressive vector compression for high-accuracy vector map data

With the increase in the number of applications using digital vector maps and the development of surveying techniques, a large volume of GIS (geographic information system) vector maps having high accuracy and precision is being produced. However, to achieve their effective transmission while preserving their high positional quality, these large amounts of vector map data need to be compressed. This paper presents a compression method based on a bin space partitioning data structure, which preserves a high-level accuracy and exact precision of spatial data. To achieve this, the proposed method a priori divides a map into rectangular local regions and classifies the bits of each object in the local regions to three types of bins, defined as category bin (CB), direction bin (DB), and accuracy bin (AB). Then, it encodes objects progressively using the properties of the classified bins, such as adjacency and orientation, to obtain the optimum compression ratio. Experimental results verify that our method can encode vector map data constituting less than 20% of the original map data at a 1-cm accuracy degree and that constituting less than 9% at a 1-m accuracy degree. In addition, its compression efficiency is greater than that of previous methods, whereas its complexity is lower for close to real-time applications.

A Watermarking Scheme Using Polyline and Polygon Characteristic of Shapefile

This paper presented the watermarking scheme for copyright of GIS vector map based on ESRI shape file. The watermarking scheme mainly uses polyline length or polygon perimeter distribution. We embed a watermark bit to the local mean length/perimeter of a suitable group of polyline/polygon data by changing all coordinates of vertices according to the constraint of the robustness and the invisibility. Experimental results verified that the proposed scheme has the robustness against various geometric attacks.

A crypto-marking method for secure vector map

A crypto-marking technique can be used to provide a solution to the secure transmission and storage of highly valuable and detailed vector maps. Such a solution would fulfill the requirements for integrity verification, content security, copyright protection, and authentication. However, existing methods cannot ensure the perceptual invisibility of the watermarking in the encryption domain and can leak the encryption key while decrypting a crypto-marked map. In response to these issues, we present a vector map crypto-marking method using both watermarking and progressive perceptual encryption that are independent of each other. The first watermarking step embeds the watermark using the mean of the Euclidian distance (MED) while preserving the object shape and being robust to geometric attacks. The second perceptual encryption step encrypts the progressive regions in a layer, the objects of a region, and the vertices in an object so that a direct random-access object can be enabled in the encryption/decryption processes. To attain the mutual independence of watermarking and encryption, we encrypted the attributes of objects by using random permutations of the position and orientation of the vertices while preserving the SEDs of all the objects. Hence, the watermark can be extracted in a crypto-marked map or progressive encrypted map without decrypting all the objects. From the experimental results, we found that our method is robust to attacks that damage the vector map during the decryption step and does not produce a leakage of the encryption key during the watermark detecting step. Furthermore, we found that the time required by our method is proportional to the number of objects in vector maps, 0.59 [s] for 7,765 objects and 3.52 [s] for 50,679 objects. Our MED-based watermarking takes less time (about 0.07–0.43 [s] than conventional watermarking methods while our progressive encryption takes less time, at about 0.09 [s] - 0.37 [s], than conventional encryption methods.

Biological Infectious Watermarking Model for Video Copyright Protection

This paper presents the infectious watermarking model (IWM) for the protection of video contents that are based on biological virus modeling by the infectious route and procedure. Our infectious watermarking is designed as a new paradigm protection for video contents, regarding the hidden watermark for video protection as an infectious virus, video content as host, and codec as contagion medium. We used pathogen, mutant, and contagion as the infectious watermark and defined the techniques of infectious watermark generation and authentication, kernel-based infectious watermarking, and content-based infectious watermarking. We experimented with our watermarking model by using existing watermarking methods as kernel-based infectious watermarking and content-based infectious watermarking medium, and verified the practical applications of our model based on these experiments.