A Strength Variable Encryption Algorithm for 2D Engineering Graphic Based on Discrete Cosine Descriptors and Chaos Scrambling

A strength variable encryption algorithm for 2D engineering graphics is proposed based on discrete cosine descriptors and chaos scrambling. The specific coordinates of vertices in the 2D engineering graphics are extracted to construct the corresponded complex signals. Then they are transformed by discrete cosine transformation in groups, after that, bit XOR operation is done between the selective AC magnitude coefficients and a binary sequence, which is generated from a key. Simulation and analysis results show that the key space is large, and the algorithm is sensitive to the key, plain graphics and encrypted graphics, which guarantee the security of 2D engineering graphics.