This is more an obfuscation problem than anything else. Sure, there are millions of ways to encrypt the link, but anyone with half a brain will still be able to figure out where it is in the code, even with little or no programming experience. What you need to do is add a verification routine entirely separate from the link print (and preferably hidden somewhere they aren't likely to look) that loads the script, computes a hash of its size and/or contents, and checks it against an internal hash to make sure the script hasn't been modified. Then if they remove your link, the script errors out, and most people won't be smart enough to figure out why.