I learned more about encryption and decryption. Those terms taught me how someone can access our data. Today, many face apps can steal our face and use it for other things. In my country this kind application is used for fun by people without knowing their data can be stolen. How we leave trace in the internet is very easy, someone can access the history or even cookies from search engine. It is very important to erase all things in the history to prevent traces that we left behind. I would like to learn more about unit 2 materials and hope can share what I’ve got from this course to my students.