To address the multiplicity and copyright issues on file sharing social networks, we propose a fast video copy detection algorithm using the suffix array data structure in this work. The proposed algorithm consists of two steps. In the first step, we extract robust features which are discriminative yet insensitive to various attacks. Specifically, we develop a compact one-dimensional signature based on the shot change position of video files. Unlike images and audio, the size of a video file is usually large, which makes it computationally expensive to match two long signature sequences. Thus, in the second step, we adopt an efficient matching technique based on the suffix array data structure. The proposed system can perform the sequence matching in linear time while the complexity of conventional duplicate video detection algorithms grows at least quadratically with the video length.