Disadvantages Of Digital Watermarking

Images that have been photoshopped using software such as Adobes photoshop program should carry watermarks. Many of the image photoshopped are just for practical jokes, but some are for more spurious reasons. Most of the photoshopping occurs on magazines or in hollywood to make actors or models to look close to perfect.

Steganography is art of hiding the secret message within an ordinary message and extraction of its destination. Steganography take cryptography a step farther by hiding an encrypted message so that no one finds the existence of the message. If anyone scans your data will fail to know that it contain encrypted data. Steganography maintain the secure communication between the communicating parties. There are different techniques that are used for hiding the secret data as Steganography, Cryptography and Watermarking. There are various drawbacks of the cryptography that are covered by the Steganography. This paper reviews the Steganography techniques and various matrices for performance analysis of Steganography techniques.

In the present world lot of multimedia data is exchanged on internet and the percent of image data in that is highest. So we need to securely transmit that and this can be achieved by Image encryption.

The rapid invention going in internet usage has resulted in the media ownership and attention towards intellectual property rights among internet users. In this paper, a Multiwavelet Transform (MWT) based video encoding is proposed. Video watermarking is the practice of inserting an encode information known as the watermark, into an original video in an imperceptible approach. The watermark converts or represents information that can protect the watermarked video, typically identifying the source or the intended destination of the video. The embedded watermark may be detected by using a watermark detector, which helps to possible an application to react to the presence (or absence) of the watermark in a video. However, the watermarked video may be processed, or attacked, prior to watermark detection. Attacks may remove the fixed watermark or make the watermark more complicated to detect. A logo watermark is composed in the uncompressed field of a video. Using IM, the watermark is embedded into the chosen multiwavelet coefficients by quantizing the coefficients. Scrambled watermarks are generated using a set of secret keys, and each watermark is embedded in each motionless scene of the video. The multi-wavelet transform uses two transformations such as Haar transform and Doubchies transform. The work is done with the help of designed user interface. This method extracts the secret message correctly and this provides better performance.

Steganography is a Greek origin word that means stegos meaning cover and grafia to which classified as cover writing. Steganography is hiding a secret message into other information such as sound, image and video. It is also known as invisible communication. In addition, steganography is related to two technologies which are watermarking and fingerprinting. Both these technologies provide the same goals which are mainly used for intellectual property protection.Thus, both are different in algorithm requirements. Watermarking provides a hidden copyright protection by owner whereas the fingerprinting used a copy of the carrier object and make it as unique to the different customer.

Steganography has been around since 1980’s. Various tools and software’s are available for Steganography as well as Steganalysis. The most common form of steganography is on digital images. For digital images there exist many steganographic techniques and furthermore there exist a lot of approaches to detect steganography in digital images. In this paper we will be looking at many tools comprising from various digital domains but we fund that almost all of the tools had support for image files. With the increasing number of new steganographic algorithms and methods for detecting steganography, the issue of comparing security of steganographic schemes in a fair manner is of the most importance. A fair benchmark for steganography should only

Since from the earlier times, people are bothered about how to securely transmit secret messages. Both Cryptographic techniques and steganographic techniques are used to achieve this aim. In cryptography, the existence of the encrypted message is visible to the world, whereas in Steganography, only the sender and the receiver know the existence of the message. Darrel Hankerson, Alfred Menezes, and Scott Vanstone explained the various arithmetic behind elliptic curves and addresses some issues that arise in ECC implementation in detail [1]. Lawrence C. Washington provides an introduction to both the number theoretic and the cryptographic sides of elliptic curves. To securely transfer text and image through the network, various techniques have been developed in recent years using Elliptic Curve Cryptography [2]. S. Maria Celestin Vigila and K. Muneeswaran proposed an image encryption algorithm using ECC. They generated the values of k and nB by a random number generator, Comparative Linear Congruential Generator (CLCG) to give credibility [3]. Ali Soleymani, Md Jan Nordin, and Zulkarnain Md Ali creates a mapping table which has the intensity values ranging from 0 to 255 along the row and the corresponding columns of each row contain the elliptic curve coordinates. All the pixels of an image are mapped to related points on the elliptic curve using the table and encryption is done using receiver’s public key. To view the cipher image, we refer to the mapping table and find the

Cryptography is defined as the art or process of writing in or deciphering secret code: any system of secret writing. Encryption is used in electronic systems to achieve privacy and authentication of information. The privacy requires, two questions need to be answered: what are the consequences of unauthorized access to or disclosure of the valuable information, and how often the possibility of unauthorized access to or disclosure of information. Authentication addresses the issues of whether data is from the correct source or if it has been unauthorized with. Functions embedded with in cryptographic systems help ensure data integrity by guaranteeing authenticity of a message and allowing the use of digital signature, a data block attached to a message that binds the message to a sender so that it can be verified by the receiver or others.

steganography and cryptography are distinctive sorts of strategies utilization to send secure information transmission. Steganography is the craftsmanship and art of concealing information into distinctive bearer records, for example, pictures, features, sound, content and so forth. In cryptography, there is parcel of degree to discover mystery message that we send by outsider

A Digital image watermarking systems have been proposed as an efficient means for copyright protection & authentication of digital image content against unintended manipulation (spatial chromatic). Watermarking techniques tries to hide a message related to the actual content of the digital signal, watermarking is used for providing a kind of security for various type of data (it may be image, audio, video, etc). Digital watermarking generally falls into the visible watermarking technology and hidden watermarking technology visible and invisible watermarks both serve to deter theft but they do so in very different ways.

The challenges are to introduce a digital watermark that is both transparent and highly robust to common signal processing and possible attacks. The two basic requirements for an effective watermarking scheme robustness and transparency conflict each other. An effective watermarking scheme is achieved by the incorporation of Human Visual System (HVS) models into watermarking scheme using JND. Just Noticeable Distortion (JND) gives us a way to model the HVS accurately and to set a trade-off between two conflicting requirement robustness and imperceptibility [19].

Secret sharing is a scheme that permits a secret message to be shared among a set P of n participants. The secret is shared in such a way that only qualified subsets of P can recover the secret, any nonqualified subset has no information on the secret. We take into consideration, the problem of encrypting pictures and printed texts such that it is perfectly secure without the hassle of using cryptographic computations. In 1979, Shamir [7] and Blakley [8] introduced the concept of a threshold scheme. A (k, n) threshold scheme is a method whereby n pieces of information of a secret key k, called shares are distributed among n participants so that the k cannot be re constructed from the knowledge of fewer than k shares. In 1995 Naor and Shamir [1] proposed a new type of cryptographic scheme, which could encode and decode secret images without any cryptographic computations. The reason this scheme was considered remarkable was that the secret message

The main goal of using the Image encryption is to avoid drawing attention to the transmission of hidden information. Storing the critical data in its original format is subjective to many risks. The embedding algorithm is used to embed the secret information in the image selected. Hashing is used to secure the sensitive information.

A multi-resolution watermarking method based on the discrete wavelet transform for copyright protection of digital images was presented by Zolghadrasli and S. Rezazadeh [21]. The watermark employed was a noise type Gaussian sequence. Watermark components were added to the significant coefficients of each selected sub band by considering the human visual system in order to embed the watermark robustly and imperceptibly. They enhanced the HVS model by performing some small modifications. The extraction of the watermark involved the host image. They measured the similarities of extracted watermarks using the Normalized Correlation Function. The robustness of their method against wide variety of attacks was illustrated.

DIGITAL image watermarking has become a necessity in many applications such as data authentication, broadcast