I have to make a file and store some data(string) in it. I want that no one will be able to understand what is written in the file by openning it as txt . like he will get text as ;vnzlghaog\GH;OLFJHQ686596- in the file. So how do I go by doing the data formating. I tried it as is done in C++ by adding numbers to ASCII value of the character, but that gave error in JAVA. Can anyone plz help me with this problem.