Towards a Telltale Watermarking Technique for Tamper-Proo ng

In this paper we present a novel fragile watermarking scheme for the tamper-proo ng of multimedia signals. Unlike previously proposed techniques, the novel approach provides spatial and frequency domain information on how the signal is modi ed. We call such a technique a telltale tamper-proo ng method. Our design embeds a fragile watermark in the discrete wavelet domain of the signal by quantizing the corresponding coe cients with user-speci ed keys. Tamper detection is possible in the localized spatial and frequency regions of the given signal. We provide analysis, simulations and comparisons with two other tamper-proo ng methods to show the potential of the proposed approach in detecting and characterizing the distortion imposed on the signal.