[vaniaspeedy]

--- edit ---
So, it seems like this idea has been done by ixtab, that wonderful coder. Here's a link for the patch.
https://www.mobileread.com/forums/sho...d.php?t=175512

The tweak protects individual books. More info and analysis about it here:
https://www.mobileread.com/forums/sho...0&postcount=89

--- original post ---
There's been an idea of password protecting collections originally brought up in this thread: https://www.mobileread.com/forums/sho...2024093#post21

Copy of the post in spoiler:

Spoiler:

Originally Posted by kindleholic

What about instead of "moving" the files from one folder to another "in-the-field" explore the possibility of having password protection for Collections, or for selected book?

I use it and my friends would like to borrow it to read specific books, lets say I open the book for them, so they would have to go back to Menu and browse for other Collections or Books, and if they want to open them, VOILA! password protection.

There are many reasons to implement a system of password protecting some books or documents, no need to use encryption for the file, just protect it from access on-the-go.

Let me know how possible is this. I am learning Linux, but I am far away to being able to write such application by myself. Still if there is anything that I can contribute, I am more than happy to do so.

This is a fantastic idea! This is more java than linux though, since on the linux end the most I can do is move files. The user end of the kindle is mostly java and html (see here), so this hack would involve creating some code that could intercept the action of opening a collection and prompt for a password. I know on the iOS platform "mobile substrate" is a prime example, however I'm not sure if anyone has created a similar tweak for the kindle.

I have a limited understanding of java, but I think this is very doable. The skeleton code would be like this:

Function.onClick() { //when someone clicks on a collection, do this
    passwordPrompt(); //prompt for a password
    openCollection(); //or do whatever it is the kinlde does on click

}//end Function.onClick

Function.passwordPrompt(){
// check if this is a protected collection
// if no then quit
// if yes continue
// prompt for password (using an html popup?)
// check if password is valid
 if (Valid)
   open collection // just use break
 else
   quit //with non-zero exit code
}//end passwordPrompt

*Note - this is dummy code, none of it actually works

Can someone post a hint or two on where to get started? I don't really want to decompile, edit, and compile the GUI. Is there a way to inject code, like how iOS uses mobile substrate? Any input appreciated. Thanks!