P.Sathiyamurthi, Dr.S.Ramakrishnan, S.Sharmila, B.Sandhiya
Our project deals with the speech encryption based on three level of permutation using three different chaotic mapping functions such as Bernoulli’s map, Henon map and Arnold Cat map to generate a complex secret key algorithm First, the speech input is sampled with ‘N’ number of samples. The samples are constructed into (m x n) matrix called original block, where m represents number of rows and n represents number of columns. This original block is randomized by permutation technique in (m-1) levels using PN sequence and one cyclic shifting operation. The PN sequence, generated by three different chaotic mapping functions is sorted and corresponding index is taken for shuffling the values of (m-1) rows. Any one of the row is shifted for three steps in cyclic manner among (m-1) rows. In order to improve the complexity of this algorithm two dimensional chaotic mapping techniques are preferred The proposed system is highly secured with more complex key and minor delay. The decryption process is the reverse operation of the encryption algorithm, carried out without disturbing the intelligibility of the original speech