The word security has many meanings; the need to hide personal information, user authentication and data encryption are all subjects related to the security topic. We can think, for instance, about what would happen if we download a malign midlet that, at a certain time, starts sending SMS messages to a specific phone number giving away personal information about our agenda or other data stored in our device. In that case the damage affects both privacy and money. In this module we’ll talk about what the MIDP 2.0 specification tells us about security, and we’ll learn how to sign a MIDlet Suite to grant the execution of operations that usually the midlet may only run after a user confirmation. Then we’ll create a simple application and we’ll observe how it runs: our goal is to compare the behavior of a signed and of an unsigned application. Read more »