The recent advances in multimedia technology demand protection of digital images from unintentional manipulation for content integrity, copyright, and ownership. Digital watermarking technique has wide acceptance in the industry for anti-piracy, ownership verification, and digital image authentication. There have been a large number of schemes in the literature proposed for digital watermarking using non-cryptographic and cryptographic primitives. Use of Least Significant Bits (LSB) is one of the oldest but classical approaches for digital image authentication. Although LSB approach is efficient, it does not provide adequate security. Cryptographic primitives such as hash function, digital signature, and message authentication codes have been used in several applications including multimedia for data authentication. Digital signature-based image authentication provides strong security, but the approach requires managing public key infrastructure, which is a costly operation. Partial data protection is also an optimal approach for protecting important data while leaving unimportant data unprotected. Considering security weakness of the LSB-based approach and cost overhead of the public key-based approach, the authors present in this chapter a digital image authentication scheme using LSB, keyed hash, and partial encryption. They show that the proposed watermarking scheme is secure and efficient in comparison to other related schemes.
A Buyer-Seller Digital Watermarking Protocol without Third Party Authorization