Abstract: A robust watermarking authentication algorithm is proposed with the value of visual masking as th quantization size. The security depends on hiding keys rather than quantization sizes which now can be opened. Therefore, it avoids some security demerits when using human visual characteristics. Furthermore, our scheme is able to distinguish common image processing from malicious tampering, and even to indicate the area where the malicious tampering arises on the basis of the erro image of watermarks.

Key words: watermarking authentication, robust watermarks, the value of visual masking