Text steganography method based on automatic selection coding and dynamic word selection strategy

A text steganography method based on automatic selection coding and dynamic word selection strategy was proposed for the inflexible text coding method and candidate word increasing number leading to the low quality of generated steganographic text.Steganographic translations was generated based on Transformer’s neural machine translation model.In generating steganographic translations, fixed-length coding and Huffman coding were used to establish the mapping relationship between candidate words and codewords, and dynamic word selection based on the probability difference threshold was achieved by calculating the probability difference percentage between steganographic words and normal words.Finally, the size of the two generated steganographic translations Sacrebleu was compared to realize the automatic selection of coding mode.The experimental results show that the proposed method can generate steganographic translations with high fluency and readability.When the embedding rate is 11.19%, the Sacrebleu of the steganographic translation reaches 10.53.