In this work, we focus on a watermark sharing scheme using error diffusion called DHCED, and try to overcome some drawbacks of this method. The proposed method simultaneously generates carrier halftone images that share the watermark information by selecting the minimum error caused in the noise function for watermark embedding. Also, the proposed method shuffles watermark image before embedding not only to increase the secracy of the embedded watermark information but also improve the watermark detection ratio as well as the watermark appearance in the detection process. We verify the superiority of the proposed method through computer simulation using some benchmark images.