21-09-2012, 03:47 PM
Digital Signature and Watermark Methods For Image Authentication using Cryptography Analysis
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Abstract
The digital signature and watermarking methods are used for image authentication. Digital signature
encodes the signature in a file separate from the original image. Cryptographic algorithms have suggested
several advantages over the traditional encryption algorithms such as high security, speed, reasonable
computational overheads and computational power. A digital watermark and signature method for image
authentication using cryptography analysis is proposed. The digital signature created for the original
image and apply watermark. Images are resized before transmission in the network. After digital signature
and water marking an image, apply the encryption and decryption process to an image for the
authentication. The encryption is used to securely transmit data in open networks for the encryption of an
image using public key and decrypt that image using private key.
Introduction
Digital Signature
Digital signature is a sort of Cryptography. Cryptography means keeping communications
private. Its mainly used for the converting of the information is encryption and decryption. No
one can’t access the information without access key.
The main process of the digital signature is similarly as the handwritten signauture.its like
paper signature and it having the digital certificate using this verifies the identity.
Watermarking
Watermarking is a sub-discipline of information hiding. It is the process of embedding
information into a digital signal in a way that is difficult to remove. It’s providing copyright
protection for intellectual method that’s in digital format.
Cryptography
The cryptography is providing better mechanisms for information security. In this analysis to
provide the public and private keys for recovery the original information. The ability store and
transfer sensitive information. By using the different encryption methods for generating public
keys, decryption using for private keys.
This method applied to digital signatures and watermarking for to provide high security in
transactions.
Cryptography
An encryption system is also called a cipher, or a cryptosystem. The message consists of
plaintext, and cipher text. Denote the plaintext and the cipher text by P and C, respectively. The
encryption procedure of a cipher can be described as C = EKe (P), where Ke is the encryption key
and E is the encryption function. Similarly, the decryption procedure is P = DKd ©, where Kd is
the decryption key and D is the decryption function. For public-key ciphers, the encryption key
Ke is published, and the decryption key Kd is kept private, for which no additional secret channel
is needed for key transfer.
Conclusion
Digital signature and watermark are two techniques used for copyright protection and
authentication, respectively. In this paper a digital signature and watermark methods are used
cryptography analysis proposed for image security. Experiments show our scheme is robust to
reasonable compression rate while preserving good image quality, and capable to authentication.