Reduction of distributed data size in audio content fingerprinting (CoFIP)

A method to reduce distributed data size in audio content fingerprinting (CoFIP) is discussed. In CoFIP, contents are distributed to users in the form of a package consisting of encrypted watermarked component objects and an unencrypted remaining background object. The user has to purchase a digital key to decrypt only one combination of the watermarked objects from the package to generate an individualized content by combining objects and the background object. Because of the discrete wavelet transform, the data length of each scale level is reduced by 50% as the scale level increases.