关键词: 隐写术, 隐写分析, 文本, 隐写模型, 分级安全

Abstract:

For the low security and capacity shortages of steganographic methods based on the single data, a new text steganography method with hierarchical security was proposed. First, multiple types of data in the whole cover document were regarded as optional steganographic covers to build up a hierarchical security steganographic model upon the the steganographic security levels defined by taking the characteristics of different types of data and the steganalysis as evaluation criterions. Then, a security level was adaptively determined by the secret message length, and the secret message was embedded into the selected independent different types of data in a cover document with the help of the built model. Theoretical analysis and experimental results show that compared with the steganography based on single data, the proposed method has expanded the steganographic capacity and reduced the modifications of the statistic characteristics of a single type of data in the cover document when the same secret message was embedded. In conclusion the proposed method improves the security of the secret message.

Key words: steganography, steganalysis, text, steganographic model, hierarchical security