The widespread use of the broadband network has seen the realization of a new video service infrastructure. Although there are promising business opportunities, the infringement of copyrighted videos increases the importance of copyright-infringement detection methods. The technical challenge involves the vastness of the video data. In this paper, we propose a content-based copied video detection method which has a constant retrieval time linked to the size of the video data. Experimental results show its accuracy and short retrieval time on altered video data.