Content area
Full text
Abstract
Steganography is the technique of sending messages hidden in images for secured communication. The major components of a steganographic framework are secret message, cover image, stegoimage. At present, most of the steganographic methods are based on substitutions. All these approaches for hiding messages are lossy since the image will be modified without causing much visually detectable change. The other major issues yet to be addressed satisfactorily are the degree of security of the communication, key size and the payload capacity. Hence, this paper proposes a novel technique which attempts to solve all the above issues in steganography. In the proposed method, instead of substitutions we are using the notion of matches between secret data and cover image. And we also use the concept offixed frequency for each character in English. The proposed method is lossless, has infinite payload capacity, has key size which is only about 10 to 20 percentage of the message size and has improved security.
keywords: Lossless Steganography, Secure Steganography, Unlimited Payload, Less Overhead
I. Introduction
The difficulties in ensuring individual's privacy become progressively challenging with advancements in digital technologies of communication and the growth of computer power and storage. Different persons will appreciate different degrees of privacy. To protect personal privacy, various methods have been investigated and developed. Encryption is probably the most obvious one, and next comes steganography. Encryption is adaptable to noise and is generally observed whereas steganography is not.
Steganography is the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message, a form of security through obscurity [1]. The word "Steganography" is of Greek origin and means "concealed writing". The main aim of steganography is to hide the existence of the message in the cover medium. Cryptography and steganography are cousins in the spy craft family [2], Cryptography scrambles a message with the help of certain cryptographic algorithms for converting the secret data into unintelligible form. On the other hand, steganography hides the message in cover image so that it becomes invisible. Sending a message in the form of cipher text might arouse suspicion on the part of the recipient whereas an "invisible" message created with steganographic algorithms...