An invertible fuzzy scheme for securing a fragile watermark

A fragile watermark provides an effective solution to ascertain the integrity of an image. However, security of the watermark is endangered during transmission through an unsecured network. This paper aims to secure watermark by applying fuzzy model based invertible transformation to the cover image after embedding visual watermark into it. The controlled non-linear transformation permutes the watermark without distorting spatial correlation of the image space. This will neutralize any attempt to predict or copy the watermark directly from the image space, thus improving its security. By inverting non-linear transformation, spatial correlation of the watermark is restored and subsequently it can be used to check the integrity of an image. The scheme is tested using a well known least significant bit (LSB) watermarking framework.