Universal data embedding in encrypted domain

• Designing a data embedding method that is universally applicable to any encrypted signal.
• Realizing data embedding universally in encrypted audio, image and text signals with consistent carrier capacity.
• Achieving consistent and perfect reversible functionality.
• Preserving file-size of the output to that of the original encrypted (input) signal.
• Offering higher embedding capacity and outperforming the most relevant method in the literature.

In this work, a Universal Reversible Data Embedding method applicable to any Encrypted Domain (urDEED) is proposed. urDEED operates completely in the encrypted domain and requires no feature of the signal prior to the encryption process. In particular, urDEED exploits the coding redundancy of the encrypted signal by partitioning it into segments referred to as imaginary codewords (IC's). Then, IC's are entropy encoded by using Golomb–Rice codewords   (GRC's). Finally, each GRC is modified to accommodate two bits from the augmented payload. urDEED is designed to preserve the same file-size as that of the original input (encrypted) signal by embedding the quotient part of the GRC's as side information. Moreover, urDEED is consistently reversible and universally applicable to any digital signal encrypted by any encryption method. Experimental results show that urDEED achieves an average embedding capacity of ∼0.169∼0.169 bit per every bit of the encrypted (host) signal.