关键词: 联合图像专家小组（JPEG）隐写, 分频段嵌入, STC编码, 隐写分析

Abstract: In this paper, a new JPEG image steganographic algorithm is proposed based on Syndrome-Trellis Codes（STC） and multi-band embedding. Syndrome trellis codes can directly improve the security of many existing steganographic systems by improving the embedding efficiency. In the proposed algorithm, the DCT coefficients are divided into six frequency bands, including the Direct Current（DC）, low, middle-low, middle, middle-high and high frequencies. With STC, the highest embedding efficiency is achieved in high frequency band with the lowest hiding rate, while the hiding rate is gradually increased in the middle-high, DC, middle, middle-low and low frequency bands so that?the hidden message is made less detectable. The proposed algorithm is implemented and tested by using four JPEG steganalytic algorithms. The numerical results show that the secret messages hidden by the proposed algorithm are less detectable than several algorithms in the literature for the JPEG images at different levels of quality.

Key words: Joint Photographic Experts Group（JPEG） steganography, multi-band embedding, Syndrome Trellis Codes（STC）, steganalysis