The processing of measuri ng data plays an important role in reverse engineering. Based on grey system the ory, we first propose some methods to the processing of measuring data in revers e engineering. The measured d...The processing of measuri ng data plays an important role in reverse engineering. Based on grey system the ory, we first propose some methods to the processing of measuring data in revers e engineering. The measured data usually have some abnormalities. When the abnor mal data are eliminated by filtering, blanks are created. The grey generation an d GM(1,1) are used to create new data for these blanks. For the uneven data sequ en ce created by measuring error, the mean generation is used to smooth it and then the stepwise and smooth generations are used to improve the data sequence.展开更多
Model reconstruction from points scanned on existing physical objects is much important in a variety of situations such as reverse engineering for mechanical products, computer vision and recovery of biological shapes...Model reconstruction from points scanned on existing physical objects is much important in a variety of situations such as reverse engineering for mechanical products, computer vision and recovery of biological shapes from two dimensional contours. With the development of measuring equipment, cloud points that contain more details of the object can be obtained conveniently. On the other hand, large quantity of sampled points brings difficulties to model reconstruction method. This paper first presents an algorithm to automatically reduce the number of cloud points under given tolerance. Triangle mesh surface from the simplified data set is reconstructed by the marching cubes algorithm. For various reasons, reconstructed mesh usually contains unwanted holes. An approach to create new triangles is proposed with optimized shape for covering the unexpected holes in triangle meshes. After hole filling, watertight triangle mesh can be directly output in STL format, which is widely used in rapid prototype manufacturing. Practical examples are included to demonstrate the method.展开更多
Since Dalvik Executable （DEX） files are prone to be reversed to the Java source code using some decompiling tools, how- to protect the DEX files from attackers becomes an important re- search issue. The traditional ...Since Dalvik Executable （DEX） files are prone to be reversed to the Java source code using some decompiling tools, how- to protect the DEX files from attackers becomes an important re- search issue. The traditional way to protect the DEX files from reverse engineering is to encrypt the entire DEX file, but after the complete plain code has been loaded into the memory while the application is running, the attackers can re- trieve the code by using memory dump attack. This paper presents a novel DEX protection scheme to withstand memory dump attack on the Android platform with the name of Dex- Defender, which adopts the dynamic class-restoration method to ensure that the complete plain DEX data not appear in the memolT while the application is being loaded into the memory. Experimental results show- that the proposed scheme can protect the DEX files from both reverse engineering and mem- ory dump attacks with an acceptable performance.展开更多
文摘The processing of measuri ng data plays an important role in reverse engineering. Based on grey system the ory, we first propose some methods to the processing of measuring data in revers e engineering. The measured data usually have some abnormalities. When the abnor mal data are eliminated by filtering, blanks are created. The grey generation an d GM(1,1) are used to create new data for these blanks. For the uneven data sequ en ce created by measuring error, the mean generation is used to smooth it and then the stepwise and smooth generations are used to improve the data sequence.
文摘Model reconstruction from points scanned on existing physical objects is much important in a variety of situations such as reverse engineering for mechanical products, computer vision and recovery of biological shapes from two dimensional contours. With the development of measuring equipment, cloud points that contain more details of the object can be obtained conveniently. On the other hand, large quantity of sampled points brings difficulties to model reconstruction method. This paper first presents an algorithm to automatically reduce the number of cloud points under given tolerance. Triangle mesh surface from the simplified data set is reconstructed by the marching cubes algorithm. For various reasons, reconstructed mesh usually contains unwanted holes. An approach to create new triangles is proposed with optimized shape for covering the unexpected holes in triangle meshes. After hole filling, watertight triangle mesh can be directly output in STL format, which is widely used in rapid prototype manufacturing. Practical examples are included to demonstrate the method.
基金supported by ZTE Industry-Academia-Research Cooperation Funds
文摘Since Dalvik Executable （DEX） files are prone to be reversed to the Java source code using some decompiling tools, how- to protect the DEX files from attackers becomes an important re- search issue. The traditional way to protect the DEX files from reverse engineering is to encrypt the entire DEX file, but after the complete plain code has been loaded into the memory while the application is running, the attackers can re- trieve the code by using memory dump attack. This paper presents a novel DEX protection scheme to withstand memory dump attack on the Android platform with the name of Dex- Defender, which adopts the dynamic class-restoration method to ensure that the complete plain DEX data not appear in the memolT while the application is being loaded into the memory. Experimental results show- that the proposed scheme can protect the DEX files from both reverse engineering and mem- ory dump attacks with an acceptable performance.
