Securing client side code

I'm in the process of dev开发者_如何学Pythoneloping an application that uses client side code (js to be specific), which needs to be secured. I.e. so that a user cannot steal the code and reuse it. Obfuscation is not an option, as I need the code to be fully secured (with encryption). After extensively scouring the internet for a solution that allows js encryption I have come come to the conclusion that this proprietary code can only be executed server side to ensure its security.

Does any one have any other ideas or solutions, that would relieve the server from having to process things that otherwise could be done on the client with js. Executing some of the code on the server is an option, but resources are limited. Another issue is that it would need to be something like "server side js" i.e. the user experience is not changed.

If the code is client side, they have the code. Period. That's how the internet works.

If you want to protect it from the end-user, then yes, you need to keep that on the server side. Alas, that will change the user experience. There really isn't a way around that, though perhaps via judicious AJAX calls you can find a happy medium.

Nope, it sounds like you've pretty much got the gist of things. Use the server to process anything that needs to be done securely. Use javascript to display the data sent from the server.

I don't know what application you're working on, but typically efforts to offload significant processing onto the client side involve so much data transfer that the server has to do more work in the long run. Can I ask what kind of processing you're wanting to do client-side?

The user experience would have to be changed for a server-side solution, simply by the fact that you'd be running code on a different box, with a network between the two. The latency will be different. It may be good enough, of course, but it's hard to say without knowing what kind of app it is.

The closest I can imagine is hosting some sort of JavaScript engine within an otherwise-secure application... but you can tell from the state of the games industry's attempts how easy they've found it to make unhackable client code. Basically, if it's going to run locally, the code has to be there to execute... and that means it can be inspected. All you can do is make it harder.

You could encrypt your javascript and then decrypt&eval it on the client side. If it´s a private application, you could use a password for the encryption, so anyone without password could not decrypt it. Otherwise you should make it really complex.

Apart from standard JS obfuscation which is discussed e.g. here: https://stackoverflow.com/questions/2285593/how-to-sell-and-protect-software-that-has-easily-visible-source-like-javascript this is close to impossible to do.

I would tend to question whether there really is a need to protect the client side code in the first place. What makes it so unique that this is necessary? Any kind of sensitive data manipulation should be done on the server side anyway, as every obfuscation method will always be only imperfect protection.