High Payload Steganography: Surface-Fitting The Transform Domain

Abstract

Recent steganography schemes have shown that transform-based techniques can hide with relatively high capacity ratios while achieving acceptable stego quality. These techniques tend to hide in high-frequency areas exploiting some features provided by transform techniques such as the strong compaction property which concentrates the energy of a signal in low-frequency coefficients, leaving a large area of insignificant coefficients in the high-frequency area. Thus, conventional techniques replace these insignificant coefficients with the secret data. However, these high-frequency components of a signal do still contribute to obtain the composite signal. Thus, this paper proposes a hiding strategy which re-shapes the secret data to the same shape as the high-frequency components rather than simply replacing these components with secret data. This reshaping process should preserve the structure of the signal, and thus outstanding stego quality can be obtained while hiding with very high hiding capacities.