Improved adaptive partial-matching steganography for Voice over IP

摘要: In Voice over IP scenarios, adaptive partial-matching steganography (APMS) is an effective approach to balance steganographic transparency and bandwidth, in which the strategies involved, however, have not achieved optimal performance yet. Therefore, this paper, we try improve APMS from three aspects. First, when current partial similarity value (PSV) falls between two given substitution thresholds, embedding process guided with unequal probabilities increased PSVs instead of identical probabilities, enhances chances cover parts larger PSVs. Second, for considered unsuitable information hiding original strategies, matrix encoding strategy employed conceal secret messages no more than one bit changed, improves usage rate while maintaining high efficiency. Third, flag bits, encrypted form message added into comprehensive evaluation matching, makes efficient. The proposed are evaluated ITU-T G.711 (A-law) as codec speech, compared ones some existing approaches. experimental results demonstrate that improved can strike excellent balances significantly outperform both former other previous Furthermore, detection tests show they outstanding steganalysis resistance.