Passing arguments into Storyline and between Storyline modules

I am working to setup a series of modules, where the user selects once (in the first module) the type of content they want to view, such as healthcare examples, automotive examples, or company proprietary examples which would all be contained in the same webinar. Note that a password would be critical for limiting access to proprietary examples.I can set up a constraint on a variable to control the flow.However, this would not work if the user can ever view the code to discover the access codes of other users. Also, it would be nice if the user could enter the code the first time they open a module, and then have that code associated with their account. This way, if they open another module the content that they can view is already determined.

Can values be passed into Storyline content in a way that is secure?

Can passwords be associated with individual accounts than can open more than one module?

Are the logical tests in the Storyline flow control sufficiently secure that users can't detect secure information?

Any info on these subjects would really help!