How to hide or lock away the images from the player?

The game is a "match the word to a displayed image by typing the word" game.

The reason why I do not want them to see the images inside the game folder is because the answers to each image is in fact the name of the image itself.

The game is written in Java.

1) Is there an universal technique to hiding the images that does this for all programming languages?

2) Or is every technique different from every programming languge?

3) Is this hiding technique the same as hiding game save state of the player?

What is this technique called?

Anything you put on the user's machine is impossible to perfectly hide. That said, you're just wanting to hide the data from regular users, not from more advanced users.

There's no real technique for that, you just find some way of packaging your data. Zipping them up in a .zip file is a common way (and then renaming the .zip extension to something else just for fun), but I think in Java you can actually store your image files in the .jar itself. I don't use Java myself, but try googling for "packing resources in a jar" or use similar search terms.

If its just the filenames then you could provide something to automatically calculate a hash value at build time to replace them and only refer to them by that value and then possibly stuff them into an archive. Also make sure only the hash values are stored in the compiled code.

Though you seem to need those values later for providing the answers which means they need to be stored somewhere. I think you could put them in some of the lowest bits of the image files if you use a lossless format.

Thanks for the feedbacks guys!