If you don’t want compromising pictures of yourself to get into the wrong hands, the best advice is to not take those compromising pictures in the first place. That’s the unfortunate truth of the internet. It is a wonderful tool that allows the limitless spread of information, but at the cost of spreading literally everything.
You can hide behind layers of security and encryption, but if you’re a popular target, those walls will eventually come crashing down. If you’re a well known person, don’t take that risk, it’s just not worth it in the end. Put your phone away, and put your clothes back on; that’s the best security advice I can give.