Effective Security Mechanism for Audio Steganography
Today's Computer world ensures security, integrity, confidentiality of the organization's data to a very large extend. Cryptography is being used by organization in order to transmit a secret message successfully without being caught up by the enemies. Cryptography has evolved rapidly from the ancient times to the modern world. The information which is being transmitted from one place to another is vulnerable to various types of active and passive attacks. Therefore, the security of the
... ion is one of the most challenging aspects of communication in today' time. A hybrid method for audio steganography (using modified Direct Sequence Spread spectrum) and cryptography (using advanced random permutation with multiple key applications) has been proposed in this paper. UGC Approved Journal with a pseudorandom signal. It is then interleaved with the cover-signal. In frequency-hopping SS, the audio file's frequency spectrum is altered so that it hops rapidly between frequencies. The steps for implementation of proposed method are as follows: A. AUDIO WATERMARKING A1. EMBEDDING OF WATERMARK First of all read cover audio signal and get equivalent 2D matrix & calculate size of matrix i.e. rows and column. Read watermark image and get equivalent 2D matrix & calculate size of matrix i.e. rows and column. Convert watermark matrix into binary matrix & reshape binary matrix into row matrix. Get spreading size by multiplying spreading factor i.e. 2 with total number of elements of binary watermark matrix and generate a random binary key sequence according to spreading size, so as to provide security. Encode watermark matrix by Binary XOR-ing of row vector watermark matrix with key sequence. Now, encoded watermark matrix has a double size as compared to that of original. If cover image is too big then divide cover image matrix into two parts. Select a block size, which must be suitable to the size of first part of cover image matrix & divide cover image matrix into first and second part. Segmentation of first part matrix into an array of sub-matrix is given below. Each sub-matrix has a specific number of elements which depends upon block size. Application of Discrete Cosine Transform (DCT) on each element of all the sub-matrices. Embedding of watermark by multiplication of encoded watermark matrix with cosine transform matrix. Join reconstructed matrix with second part of cover image matrix and getting of embedded image and resize embedded image according to original audio cover signal. Plot frequency coefficients of both audio cover signals, so as to make comparison.