In this paper, a novel scheme for video scrambling is introduced for Distributed Video Coding. The goal is to conceal video information in several applications such as video surveillance and anonymous video communications to preserve privacy. This is achieved by performing a transform domain scrambling on both Key and Wyner-Ziv frames. More specifically, the sign of the scrambled transform coefficient is inverted at the encoder side. The scrambling pattern is defined by a secret key and the latter is required at the decoder for descrambling. The scheme is proven to provide a good level of security in addition to a flexible scrambling level (i.e the amount of distortion introduced). Finally, it is shown that the original DVC scheme and the one with scrambling have a similar rate distortion performance. In other words, the DVC compression efficiency is not negatively impacted by the introduction of the scrambling.