Secure In-App purchases

Radiesel

Hi together,
I am not yet very familiar with In-App purchasing, but however as far as I understand at some point I am getting a "Transaction successful" event. Lets assume, this is working.

Now, if the user buys lets say 5 items, I have to store that information somewhere. Right now, I would store the number of items by io-functions into documents folder on the device. I would reduce that number if the user has used one or more items.

The main question is, how can I avoid or at least make it more difficult to the user that he doesn't use any kind of tools to increase that number within the device? Are there any guidelines to handle In-App purchased items?

Thanks in advance!
Michael

moopf

Well the biggest problem is that your Lua code is not encrypted (it is on the Gideros roadmap I believe) so whatever method you try to use to encrypt or encode the information you store in a file your app creates it won't be particularly difficult for somebody with the intention of changing the values to work out the algorithm you're using.

Having said that, don't get too hung up on it. Many very popular games (Tiny Tower for instance) use plain files for this information so it's possible to bypass lots of things, increase your money etc. with simple editing (in Tiny Tower you can even change your device's time to hurry things along)

Most people won't try to bypass things however, the majority don't have the knowledge.

Radiesel

Hmm, OK, out of the box, I wouldn't know myself ;-))

thanks!
Michael