| Popis: |
Data security is considered as one of the prime concerns in digital communication era. Steganography and cryptography are two parallel approaches adopted for protecting such data. Steganography camouflages the secret data into a cover media while cryptography converts it into an unreadable format. In this paper, we propose a non-sequential steganographic scheme by employing Perfect Square Quotient Differencing, where the secret data is embedded non-sequentially in two parallel phases on the two counter parts of a pixel, quotient and remainder. In phase-I, we apply Two Least Significant Bit (2LSB) replacement on the remainder part whereas perfect square quantization is applied on the quotient part in phase-II. A new format of range-table has been introduced to estimate the length of the embedding bits in phase-II. The proposed method secures high embedding capacity (on an average 3bpp) due to 2-phases of embedding at every single pixel. The proposed algorithm has been experimented on a large set of color animated image sequences. To establish the algorithmic efficiency, Peak Signal to Noise Ratio, Mean Square Error, Universal Image Quality Index and Payload Curve have been used as performance measure. The proposed method outperforms in all performance measure as compared with few modern steganography methods. Steganalysis have also been carried out to establish the robustness and security of the proposed against various security threats. Proposed algorithm can be used to protect digital documents in cloud based storage platform. |
