Ok here's what i need to know. How do i know if a games packets are encrypted. Suppose i have packet sniffer and i get the packet for sitting. what will an encrypted packet look like, and what will a non encrypted packet look like? thanks.

What possible legal reason could you have for asking this question???

There isn't an easy way to do this, and most of the time a compressed format will look much the same as an encrypted one.

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Original post by fastlane69 What possible legal reason could you have for asking this question???

Perhaps he intends to reverse engineer a network protocol to develop a compatible product?

I second what doynax said.

The reason is to create an emulator for a game, and to create the server software i need the packets

What game is it?

I stand by my original post:

If he is legally reverse engineering a network protocol, he would have access to this information already. And trying to develop a compatiple/competitive product by reverse engineering just can't be legal.

And the fact that he is trying to make a server emulator for what I can only assume is a current game pretty much means screams that he is not doing it legally, for again if it was legal, he would have access to this information already.

This seems like a question only someone who wants to hack a current game would ask...

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Original post by fastlane69 If he is legally reverse engineering a network protocol, he would have access to this information already. And trying to develop a compatiple/competitive product by reverse engineering just can't be legal.

Actually, it is. There are special rules for limited reverse engineering in order to develop in compatible products (consider reverse engineering Word's document format in order to write a word processor). And apparently you can't give up that right in a EULA either.

Still, I'm mostly just trying to decipher what my college textbook says on the subject so I'm hardly qualified to give legal advice.

Nobody on GameDev.net is a licensed legal professional, and thus you can't get legal advice here. You should also consider that the laws (especially related to reverse engineering) vary wildly between countries. The DMCA in the US apparently explicitly prohibits certain kinds of reverse engineering, whereas the laws of the European Union apparently explicitly makes certain kinds of reverse engineering legal.

Gamedev.net is about sharing information about how to create games. As long as we can do that, in general, without breaching confidentiality agreements, then we should post information we have. However, telling people how to break specific protections for specific games would be a very bad idea -- especially given that GameDev.net is hosted in the US.

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Original post by Huwhat Ok here's what i need to know. How do i know if a games packets are encrypted. Suppose i have packet sniffer and i get the packet for sitting. what will an encrypted packet look like, and what will a non encrypted packet look like? thanks.

An encrypted packet looks different than the unencrypted data. That's about all you can say. That's the entire point in encryption. There isn't a "The following 16 bytes have been encrypted with 3DES and the key used was ......" tag on the packet, you know. [wink]

A nonencrypted packet will look identical no matter how many times you send it. An encrypted one *may* vary (depending on how you encrypted, whether the key is the same, and other factors)

And in a nonencrypted packet, you will *usually* be able to detect some kind of pattern. Some bytes change all the time, others stay the same until some specific event occurs. And yet others always stay the same, no matter what.