Capacity and security for imperfect batch steganography

Batch steganography aims to conquer the limitations of capacity and security of data hiding with a single cover, and it is to spread secret information among a large number of covers, having improved basic algorithm and strategies of stegosystem. The steganographic features of batch covers and single cover were compared to propose a theoretic model for batch steganography. According to Kullback-Leibler divergence of batch steganography, the relationship of imperfect steganographic capacity with a formalized number of batch covers and embedding strategies was put forward. The maximum payload of an imperfect batch steganographiy (IBS) was determined by the number of batch covers and the base cover set and proved by formulations, and compared with capacity of noisy channels. The results show that the model under constraints of IBS is feasible for batch steganography. The research results are helpful for stegosystem design and steganalysis.