haha yeah, you would not want to rely on it for security, most children could break it. I do think it is important to teach people from the beginning with simple methods before moving on to the complex. Another reason I like covering the caesar cipher is because of ROT 13 which was used on message boards in the 1980s as well as the fact that is a great example of a substitution cipher...but dont worry everything in my series will get more modern and complex as we go...must crawl before walk. Thanks for your comments, glad you find this stuff interesting!