—Digital watermarking is a technique for protecting intellectual property of digital information. However, when a work is created by multiple authors, digital watermarking may suffer some problems. When each author embeds his/her watermark, it is highly probable that the latter watermark will compromise the former one. Additionally, it is reasonable that no author can prove the ownership alone since all authors own the work jointly. In this paper, we will propose a copyright protection scheme, which is suitable for co-authored works and without drawbacks of digital watermarking. Our scheme integrates discrete cosine transform and visual cryptography to meet the requirement of robustness and security. The experimental results show that our scheme can resist some common attacks successfully.