16-07-2012, 05:02 PM
SECRET IMAGE SHARING USING PSEUDO RANDOM SEQUENCE
SECRET IMAGE SHARING USING PSEUDO RANDOM SEQUENCE.pptx (Size: 101.01 KB / Downloads: 65)
INTRODUCTION
In the present era of computers and fast communication,one needs to protect communicated information (message or plain text) from unauthorized user, while sending it through any electronic media.The data encryption standard and Rivest, Shamir, Adleman (RSA) and Advanced Encryption Standard (AES) are three representative methods.
Apart from cryptography, steganography provides another way to keep the data secure. The Steganography consists of techniques to allow the communication between two persons. It hides not only the contents but also the existence of the communication in the eyes of any observer.
The new technologies and, in special way, the information networks require more and more sophisticated strategies in order to prevent the message privacy. In this context, digital images and audio is excellent candidate to turn into containers of the messages, since the bits of a secret text message can be superimposed, as slight noise, to the bits employed for coding a digital image.
Features of the project
Describes the latest techniques algorithms and solutions for image sharing and visual cryptography.
Provides extensive coverage of both theoretical aspects and practical applications of image sharing techniques.
Explores new techniques for visual cryptography using random grids and contrast optimizations.
Details recent advances in visual cryptography ,including probabilistic schemes and colored image sharing techniques.
Includes several application examples of image sharing for steganography and authentication.
Existing system
Advanced Encryption Standard (AES)
This is used to encrypt the secret data by the administrator. We fix block size and key size to 28 bit.
AES consists of 4 types:
Rijnadael’s internals description: The input plain text or output cipher text of block size of 128 bits is viewed as 4*4 matrix of 16 bytes arranged in a column major format. Rijndael consists of an initial round of key addition followed by 10 iterations of round transformations for key size of 128 bits. Each round transformation function is composed of four sub transformation functions: byte, substitution, row shift mixed column and add round key.
Byte substitution transformation: this is the only non linear transformation in its entire Rijnadael structure. It operates independently on each byte using a substitution table(S-box). The S-box which is invertible in nature, is composed of 2 transformations: multiplicative inverse and affine tranformation
System architecture
A system architecture or systems architecture is the conceptual model that defines the structure, behavior, and more views of a system
An architecture description is a formal description and representation of a system, organized in a way that supports reasoning about the structure of the system which comprises system components, the externally visible properties of those components, the relationships (e.g. the behavior) between them, and provides a plan from which products can be procured, and systems developed, that will work together to implement the overall system. The language for architecture description is called the architecture description language (ADL).