How can i prevent my users to edit saved json files? Do i need to do encryption?

Im saving game progress and score data to json files in my app. Since json is easy to edit and change is there a way to prent users from accessing and changing the values?

If i do encrypt i read that i need to get permission from the law or sonething. I dont want to deal with this. Is this true?

I posted in another topic with a method for encrypting the json data:  

http://forums.coronalabs.com/topic/50260-how-to-stop-cheating-for-scores-and-iap/

When you upload a build to apple it asks whether you use any encryption. I believe there is some legal stuff when uploading builds from outside the US, but I might be wrong there since someone else usually handles that side of stuff for me.

I posted in another topic with a method for encrypting the json data:  

http://forums.coronalabs.com/topic/50260-how-to-stop-cheating-for-scores-and-iap/

When you upload a build to apple it asks whether you use any encryption. I believe there is some legal stuff when uploading builds from outside the US, but I might be wrong there since someone else usually handles that side of stuff for me.