Westfeld[1] detected the stegoed–image by measuring the frequencies of PoVs(pairs of values) in the suspicious images. Fridrich[4] proposed another detection method, so-called RS steganalysis. In this paper we propose a steganographic scheme using a block cipher, which minimizes the embedding changes of a cover object utilizing not only the LSBs of the cover object’s strings but also the whole bits of the cover object. The proposed scheme is a kind of the coding scheme which minimizes changed bits for message embedding without sharing the secret code–book. The experimental result shows that the proposed scheme efficiently evades the χ ²–statistical test and RS steganalysis.