Cryptography, watermarking and steganography are among the rapidly emerging techniques pertaining to sustain, authenticate, and exhume the hidden data, especially when it is transmitted over a public network/channel. In cryptography, the message is executed and encrypted artistically that the intended message becomes incomprehensible. Whereas, water marking technique conceals the data in some cover file quite tactfully that the data engrossed in the host signal/ entity becomes imperceptible which is likely to be authenticated later on. Likewise, steganography approach veils the data in the cover signal indistinctly to deflect the interception of undesired user. The exchange of encompassed message by cryptographic system may create suspense for the intruder. But, contrary to it, in steganography the user is less attracted to the hidden information. Therefore, the harmonization of both of these technologies can produce invisible higher level of message protection. In this dissertation, the problem of imperceptibility, data rate and robustness is formulated and different approaches are proposed and investigated to solve it. In first approach, a novel technique to embed information into the audio signals is proposed. In this regard, the set of all possible values of amplitudes of audio signals are termed as “audio sample space”. An algorithm is proposed to subdivide this sample space into subspaces and the information was embedded into these subspaces. On the other hand, an algorithm for decoding on receiver side is also proposed. The algorithm has the capability to work on real time systems and provide sufficient security at commercial level. The amount of imperceptibility achieved is, quite a distinct viii benefit concerning perceptual evaluation of speech quality (PESQ). In second approach, an innovative steganography technique has been engineered named as weighted pattern matching (WPM) which is utilized to collaborate the lifting wavelet transform. The message bits are insert in the indistinguishable places that are picked from the coefficients of detail sub-bands by taking edge of the proposed WPM technique. WPM captures the correlation between the message data block and detail coefficients help us to configure the exact location that can contain the data block invisibly. The ultimate results of the experiment exhibit that the WPM technique enhances invisibility significantly in addition to lossless massage retrieval. In third approach, another sustained efficient, imperishable approach brimmed of heavy payload, named compressive weighted pattern matching (CWPM) has been invented and applied. CWPM technique has been born from the combination of compressive sensing (CS) with WPM. Use of CS provides the higher level of security and bigger payload by means of compression and encryption. CWPM holds the position where data block can be embedded on the basis of a weighted correlation. Our engineered techniques have been compared with the well-known steganography elaborated in literature review. The results ingenuity proves that all designed models are far better firm and ingratiating.