CryptoPlayerPrefs

The CryptoPlayerPrefs class is an alternative for the PlayerPrefs class, by adding cryptography. Thus, it is possible to secure sensitive data and protect them from game modification and cheating.
How to?

Simply replace PlayerPrefs.* with CryptoPlayerPrefs.*

As an example:
You could have a preference "isPremium", which is set to "yes" if premium and to "no" if not. People could modify PlayerPrefs and set straight forward "isPremium" to "yes". WIth CryptoPlayerPrefs they don't know which preference is responsible for premium activation and also don't know which value would mean 'yes'. Or you have a highscore based game and a level system. Every level gives you 5% points boost. The CryptoPlayerPrefs class makes the preferences (e.g. level) unreadable for the user and protects against modifications.
It is capable of using the Advanced Encryption Standard (Rijndael Algorithm). It also offers an XOR-option, to make the values "unreadable" for humans.