I was interviewing for a full time position with the company I am a contractor with. One of the questions I got presented with was designing an IM client. I got asked the following question: "How would you encrypt the messages so that customer service could read them if they needed to?"
I have no experience with encryption, and did not pretend to. After the interview I went to try and find information on this so that I would have a better understanding. When I attempted to look up message encryption(how-to, example, coding, java, etc) it would only bring show articles about which app you should install to encrypt your messages, why you should use message encryption apps, etc. I couldn't find how it's done or how to implement it.
I have a basic understanding of how encryption works, but how would I go about learning more(ideally without pouring through an encryption book). I would like to understand how I could answer the question I was presented with in case I ever get an opportunity like that again.