关键词: 二维码, 数字水印, 加密, 解密

Abstract: The two-dimensional code is widely applied in production security and traceability, whose ownership is effectively protected by watermark and which is also correctly recognized. The watermark in the two-dimensional code has the good features such as the invisibility and robustness and so on. Firstly, the image of two-dimensional code is partitioned into some blocks, and then each block is transformed by DCT. Secondly, the center range of every block is further transformed by SVD. At last, the image of watermark is encrypted by Logistic and Arnold Transform, forming encrypted watermark which is embedded into feature vector of SVD, and then the image of two-dimensional code with watermark is formed. The extraction of watermark from the two-dimensional code with watermark is the inversed procedure of embedding watermark into the two-dimension code. The experiments show that the watermark in the two-dimensional code can effectively resist a variety of attacks, having excellent robustness, security and invisibility.

Key words: two-dimensional code, digital watermark, encryption, decryption