I working on a simple vb application. But I want to protect it to give the user the option to use it only for a specific time. So I was thinking to make a text file with a key-code (Beside Random characters, it contains an expire date). When the application is started after this expire date, the application should close automatically.
The location where this textile is location can be the same location where the executable is running from. Does somebody of you have a good idea how to implement it? Or is there a easier way how to implement this. By its nature there is no such thing as a simple license key. You cannot keep something secret on the users system.
You can create a key (file) in a manner that makes it very, very hard to reproduce other than on your system. Then the client app 'just' has to verify the license.
If that entered key is already in the database, deny the registration. If it is not, then check to see if the correct algorithm is met. If not, deny the registration. If it is, the unlock the software and then enter the entry into the database thereby locking out any further attempts to register using that code. May 07, 2008 i have Developed an Application in vb.net. For this,i have to Generate a license Key Based on Cpu id, mother Board Id, and Mac Address. I tried this. But When i Encrypt this Three Values,i got a Result of 40 Characters. The License Key Should be between 16 to 20 characters. How i Convert this 40 Characters into 16 Characters.
Still all it takes is them to patch your code to IsRegistered = True rather than call the method. Expirys are a whole other level of concern. The first question you should ask yourself is why does it expire? Unless you have a tech support crew, why do you deserve it? – Jan 1 '17 at 20:58. If you want to give a 'Trial period' to your application you might want rather hard-code that to prevent tampering.
Then, when purchased make a modification to registry and different files (maybe downloads a few files that 'register' the application so that it recognizes itself as 'full'. To go one step further maybe periodically have the application reach out to your server and verify the license. This is a huge subject that a lot of smarter people than me can weigh in on.
I will note that this is part of a constant battle between developers and hackers trying to get around licensure.