*IF* your parents are spying on you (a very big if - I could probably figure out how to do it but I wouldn't bother because it's too much trouble), it might be more productive to sit down with your parents and ask them why they feel they need to spy on you. Are they just being paranoid? Have you done things in the past which make them not trust you anymore? etc.
Then work on a mutually agreed solution which preserves your privacy, but still gives them peace of mind that you're not secretly the leader of a gang or whatever. Simply hiding your communications from them is covering up the problem, and will probably make them more paranoid (I'm assuming they're paying for your room, board, and phone, so technically they have every right to see what you're doing with your phone).
Have a good talk with them to try to work out the problems. Not only will it make life easier, but the experience and skills you learn from doing it will help you in the future when you have to deal with uncooperative co-workers or bosses who just don't seem to understand you.
/blog.whatsapp.com/10000618/end-to-end-encryption
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