iOS Question appstore encryption documentation

In the appstore it says:
You're required to provide documentation if your app contains any of the following:

• Encryption algorithms that are proprietary or not accepted as standard by international standard bodies (IEEE, IETF, ITU, etc.)
• Standard encryption algorithms instead of, or in addition to, using or accessing the encryption within Apple's operating system

I do not understand what they consider encryption. My app uses a simple xor-based algorithm to obfuscate the main data file (a text file about 1MB that contains the lessons, it's a language learning app). Could they consider this encryption that I have to declare?