Rational dither modulation: a high-rate data-hiding method invariant to gain attacks

Abstract

A novel quantization-based data-hiding method, called Rational Dither Modulation (RDM), is presented. This method retains most of the simplicity of the conventional dither modulation (DM) scheme, which is largely vulnerable to amplitude scalings and modifies it in such a way that the result becomes invariant to gain attacks. RDM is based on using a gain-invariant adaptive quantization step-size at both embedder and decoder. This causes the watermarked signal to be asymptotically stationary. Mathematical tools are used to determine the stationary probability density function, which is later used to assess the performance of RDM in Gaussian channels. It is also shown that by increasing the memory of the system, it is possible to asymptotically approach the performance of DM, still keeping invariance against gain attacks. RDM is compared with improved spread-spectrum methods, showing that the former can achieve much higher rates for the same bit error probability. Experimental results confirm the validity of the theoretical analyses given in the paper. Finally, a broader class of methods, that extends gain-in- variance to quantization index modulation (QIM) methods, is also presented

Data hiding in audio signal using Rational Dither Modulation

“…In order to reduce that vulnerability, several schemes have been proposed [2,3]. Rational Dither Modulation (RDM) was introduced as a solution to gain attack in high-rate data hiding schemes [4], however, its performance was studied only for the Gaussian channels case without considering other kinds of signal distortions. On the other hand, Modulated Complex Lapped Transform (MCLT) is considered as an excellent domain to realize imperceptible data hiding.…”

Efficient implementation of the RDM-QIM algorithm in an FPGA

“…Rational Dither Modulation (RDM) was proposed as a possible solution to that attack by Perez-Gonzalez et al [4], in order to get a high rate data hiding method invariant to gain attacks. The embedding rule is as follows:…”

“…The problem of choosing a particular g function is an important issue due to the intrinsic nonlinearity of the quantization process, Perez-Gonzalez et al [4] suggests one subset based on Holder or l p vector-norms:…”

“…However, the main weakness of QIM is its debility against the gain attack. In order to beat that debility several schemes have been proposed [2,3,4]. Rational Dither Modulation (RDM) was introduced as a solution to the gain attack in high-rate data hiding schemes [4].…”

“…In order to beat that debility several schemes have been proposed [2,3,4]. Rational Dither Modulation (RDM) was introduced as a solution to the gain attack in high-rate data hiding schemes [4]. The basic idea behind RDM is to apply conventional Dither Modulation to the ratio of the current host sample and the previously generated watermarked sample.…”