I am glad that you have visited the course. I am not going to persuade you to buy this course as i want you to go through the preview and have a glance over introduction to Cryptography, so i you think it is worth, you should go for it. However, i tried my best to explain the course to beginners, but if you are Pro in Cryptography, this course is not for you.
Cryptography seems difficult, but i have explained it in easy manner. So, if you find anything which lacks in this course, feel free to let me know and i would be glad to update this course accordingly.