To overcome the attacking-prone drawbacks of quantization index modulation(QIM) in YASS(yet another steganographic scheme)

an improved YASS algorithm based on MSBs(most significant bits)arithmetic decoding in DCT domain is proposed.First

a secret sequence is viewed as an arithmetic coding stream and recovered by arithmetic decoding with the MSBs probability of a cover signal distributed

thus the codec reset results in a same marginal distribution between decoding stream and the cover.Then

the decoded bits are reembedded as the convention.Combined with the highly random embedding of YASS

the proposed scheme has a higher security with the first order distribution historgram between the cover and the stego minimized.Experiments demonstrate that the proposed method outperforms YASS both in capability of anti-steg-analysis and the performance of coefficient distribution historgram

which is 6.8% for YASS and 6.3% for the improved one in average. It is an effective steganographic algorithm.