Abstract: The proposed semi-fragile watermarking scheme is realized using the RS error-correcting codes and wavelet decomposition. While the encoding data of RS codes are composed of an authentication key and selected wavelet data of an image, the checked data of RS codes carry the digital watermark and are embedded into different sub-bands in the wavelet domain of the host image, achieving semi-fragility. Theoretical analysis indicates that the proposed scheme is capable of identifying the authenticators with the authentication key data.

Key words: semi-fragile watermark, RS code, error map, authentication key