This is encoding secret files within text files It is a Research Paper Implementation and I am attaching the paper which I have reffered to
It is pretty Interesting. I would suggest that it should be given a reading to understand the basics and implementation , It also suggests a lot of the other existing projects which also have pretty interesting techniques especially the Por et al (2012), Desoky (2009), Grothoff et al , Wang et al (2009),sun et al(20014) also the Wayner and Chapman &Davida Methods. My personal favourite after this one is the Por et al (2012) , it exudes a very unique and interesting technique {I chose this one because it is more viable (regarding practical solution) ...because in the other method in the cross-platform implementation some of the data will be lost which is not the case in this paper ,Henceforth I chose this paper}
It uses an impressive combination of various techniques . I would suggest that you give this paper a read (for further details ..... :'D)