<title>Watermarking protocols for authentication and ownership protection based on timestamps and holograms</title>

Abstract

Digital watermarking has become an accepted technology for enabling multimedia protection schemes. One problem here is the security of these schemes. Without a suitable framework, watermarks can be replaced and manipulated. We discuss different protocols providing security against rightful ownership attacks and other fraud attempts. We compare the characteristics of existing protocols like direct embedding or seed based protocols for different media and the required attributes of the watermarking technology, like robustness or capacity. We introduce two new media independent protocol schemes for rightful ownership authentication. With the first scheme we ensure security of digital watermarks used for ownership protection with a combination of two watermarks: a first watermark of the copyright holder and a second watermark from a Trusted Third Party (TTP). It is based on hologram embedding and the watermark consists of e.g. a company logo. As an example we use digital images and specify the properties of the embedded additional security information. We identify the components necessary for the security protocol, such as timestamp, PKI and cryptographic algorithms. The second scheme is used for authentication. It is designed for invertible watermarking applications which require high data integrity. We combine digital signature schemes and digital watermarking to provide a public verifiable integrity. The original data can only be reproduced with a secret key. Both approaches provide solutions for copyright and authentication watermarking and are introduced for image data but can be easily adopted for video and audio data as well.

Reversible watermarking with localization for biometric images

“…Potential reversibility problems associated with the limited range of values in the digital representation of the host image, e.g., overflow and underflow during addition and subtraction, are prevented by adopting modulo arithmetic [16] or a circular interpretation of the bijective transform [13]. In Type-II algorithms [14,17], information bits are embedded by modifying the selected features of the host image, for instance least significant bits or high frequency coefficients. The reversibility for the original host image is achieved by compressing the original features and transmitting the compressed bit stream as a part of the embedded payload.…”

<title>Localized lossless authentication watermark (LAW)</title>

“…Earlier methods either require the reconstruction of the original 7, 9 or require verification of multiple watermarks (digital signatures). 13 In the latter case, the use of a single authentication watermark also saves valuable reversible data embedding capacity. At the embedder, performing the reversible data embedding step before authentication watermarking offers similar computational advantages.…”

“…Dittmann et al 13 proposed an alternative protocol for the LSB compression technique. 7 They replace the signature of the whole image with two signatures that are computed from the most significant bits (MSB) of the image and the compressed version of the LSBs, respectively.…”

Ensuring Media Integrity on Third-Party Infrastructures

“…Other implementations can be found in (Fridrich et al, 2001;Fridrich et al, 2002a;Dittmann et al, 2002).…”