Watermarking Techniques for Protecting Intellectual Properties in a Digital Environment

The protection and enforcement of intellectual property rights for digital media has become an important issue in many countries of the world. There is increase in the popularity and accessibility of the Internet to record, edit, replicate and broadcast multimedia content which has necessitated a high demand to protect digital information against illegal uses, manipulations and distributions. Digital watermarking technique which is the process used to embed proprietary information into multimedia digital signal provides a robust solution to this problem. This paper reviews different aspects and techniques of digital watermarking for protecting digital contents. It also explores different application areas of digital watermarking such as copyright protection, broadcast monitoring, integrity protection etc.Facultad de Informátic

Watermarking Techniques for Protecting Intellectual Properties in a Digital Environment

The protection and enforcement of intellectual property rights for digital media has become an important issue in many countries of the world. There is increase in the popularity and accessibility of the Internet to record, edit, replicate and broadcast multimedia content which has necessitated a high demand to protect digital information against illegal uses, manipulations and distributions. Digital watermarking technique which is the process used to embed proprietary information into multimedia digital signal provides a robust solution to this problem. This paper reviews different aspects and techniques of digital watermarking for protecting digital contents. It also explores different application areas of digital watermarking such as copyright protection, broadcast monitoring, integrity protection etc.Facultad de Informátic

Fragile Watermarking using Chaotic Sequences *

Abstract I

Digital watermarking methods for data security and authentication

Philosophiae Doctor - PhDCryptology is the study of systems that typically originate from a consideration of the ideal circumstances under which secure information exchange is to take place. It involves the study of cryptographic and other processes that might be introduced for breaking the output of such systems - cryptanalysis. This includes the introduction of formal mathematical methods for the design of a cryptosystem and for estimating its theoretical level of securit

Watermarking Techniques for Protecting Intellectual Properties in a Digital Environment

The protection and enforcement of intellectual property rights for digital media has become an important issue in many countries of the world. There is increase in the popularity and accessibility of the Internet to record, edit, replicate and broadcast multimedia content which has necessitated a high demand to protect digital information against illegal uses, manipulations and distributions. Digital watermarking technique which is the process used to embed proprietary information into multimedia digital signal provides a robust solution to this problem. This paper reviews different aspects and techniques of digital watermarking for protecting digital contents. It also explores different application areas of digital watermarking such as copyright protection, broadcast monitoring, integrity protection etc.Facultad de Informátic

Watermarking security part I: theory

This article proposes a theory of watermarking security based on a cryptanalysis point of view. The main idea is that information about the secret key leaks from the observations, for instance watermarked pieces of content, available to the opponent. Tools from information theory (Shannon's mutual information and Fisher's information matrix) can measure this leakage of information. The security level is then defined as the number of observations the attacker needs to successfully estimate the secret key. This theory is applied to common watermarking methods: the substitutive scheme and spread spectrum based techniques. Their security levels are calculated against three kinds of attack

Blind Image Watermark Detection Algorithm based on Discrete Shearlet Transform Using Statistical Decision Theory

Blind watermarking targets the challenging recovery of the watermark when the host is not available during the detection stage.This paper proposes Discrete Shearlet Transform as a new embedding domain for blind image watermarking. Our novel DST blind watermark detection system uses a nonadditive scheme based on the statistical decision theory. It first computes the probability density function (PDF) of the DST coefficients modelled as a Laplacian distribution. The resulting likelihood ratio is compared with a decision threshold calculated using Neyman-Pearson criterion to minimise the missed detection subject to a fixed false alarm probability. Our method is evaluated in terms of imperceptibility, robustness and payload against different attacks (Gaussian noise, Blurring, Cropping, Compression and Rotation) using 30 standard grayscale images covering different characteristics (smooth, more complex with a lot of edges and high detail textured regions). The proposed method shows greater windowing flexibility with more sensitive to directional and anisotropic features when compared against Discrete Wavelet and Contourlets

Dynamic block encryption with self-authenticating key exchange

One of the greatest challenges facing cryptographers is the mechanism used for key exchange. When secret data is transmitted, the chances are that there may be an attacker who will try to intercept and decrypt the message. Having done so, he/she might just gain advantage over the information obtained, or attempt to tamper with the message, and thus, misguiding the recipient. Both cases are equally fatal and may cause great harm as a consequence. In cryptography, there are two commonly used methods of exchanging secret keys between parties. In the first method, symmetric cryptography, the key is sent in advance, over some secure channel, which only the intended recipient can read. The second method of key sharing is by using a public key exchange method, where each party has a private and public key, a public key is shared and a private key is kept locally. In both cases, keys are exchanged between two parties. In this thesis, we propose a method whereby the risk of exchanging keys is minimised. The key is embedded in the encrypted text using a process that we call `chirp coding', and recovered by the recipient using a process that is based on correlation. The `chirp coding parameters' are exchanged between users by employing a USB flash memory retained by each user. If the keys are compromised they are still not usable because an attacker can only have access to part of the key. Alternatively, the software can be configured to operate in a one time parameter mode, in this mode, the parameters are agreed upon in advance. There is no parameter exchange during file transmission, except, of course, the key embedded in ciphertext. The thesis also introduces a method of encryption which utilises dynamic blocks, where the block size is different for each block. Prime numbers are used to drive two random number generators: a Linear Congruential Generator (LCG) which takes in the seed and initialises the system and a Blum-Blum Shum (BBS) generator which is used to generate random streams to encrypt messages, images or video clips for example. In each case, the key created is text dependent and therefore will change as each message is sent. The scheme presented in this research is composed of five basic modules. The first module is the key generation module, where the key to be generated is message dependent. The second module, encryption module, performs data encryption. The third module, key exchange module, embeds the key into the encrypted text. Once this is done, the message is transmitted and the recipient uses the key extraction module to retrieve the key and finally the decryption module is executed to decrypt the message and authenticate it. In addition, the message may be compressed before encryption and decompressed by the recipient after decryption using standard compression tools