Securing images used in java applets

Question

I am using a java applet in my web project and some images are shown in this java applet.

I want to limit users to pull images from the web page. What are possible techniques for a client user to save images used in a java applet which is used in a browser session, except "print screen"?

Any ideas are welcome.

Thanks.

Answer 1

..What are possible techniques for a client user to save images used in a java applet

I don't know about typical end-users, but I'd do these things to circumvent several security strategies:

1. Hide them in the archives

1. Look at the source of the page
2. Discover the location of the Jars
3. Download each one by direct fetch
4. Rename them to .zip and expand them (quick & dirty), then..
5. Sell your images for causing me that much inconvenience to get them in the form I want.

That last part was sarcasm (mostly), but just wanted to make the point that if you put something in a Jar, people can get it out.

2. Hide them on the server

1. Use a packet sniffer to discover the image locations by URL.
2. Pull each image directly (etc.)

3. Encrypt the images

You might use techniques to encrypt the images, then obfuscate the code that decrypts them, but that would also fail against a determined hacker.

4. Screen grab

As mentioned already. 'Last resort' - crude, but effective.

..Any ideas are welcome.

Don't pursue such strategies. You won't achieve any form of security worth having, it will just irritate the user.

Answer 2

If the image is a bitmap inside of a jframe it'll be hard to capture it without resorting to a screen grab. Just like using it in flash the image file itself won't actually exist anywhere on the client.