Audio Encryption Using Fragile Watermarking

The main application area for digital watermarking is copyright protection. We propose a method that increases the robustness of copyright protection watermarks by persuading users not to try attacking the watermark. The method embeds two watermarks into media; a robust one and fragile one. Copy protection information is embedded into the robust watermark. The fragile watermark contains some application specific information that the user do not want to lose. The fragile watermark is constructed so that it is destroyed, if the robust watermark is attacked. The proposed method is demonstrated with a audio encryption scenario that uses the mobile phone to play protected audio files. The audio decryption keys are embedded into the fragile watermark.