Messaging Libraries?

What are the best messaging libs for OpenWrt? I would like to have encryption and exchange control messages. Further, stability is important.

I used usock in another project, and I saw that it can be very hacky. There is the option to add SSL on it, but I'm not sure if I can use it without any problems, since I don't even would use signed certificates.

I heard many OpenWrt devs are using mqtt. For now, I'm not sure about advantages and disadvantages. I need some authorization that only server gets messages I send to them and no subscribes. I believe that mqtt is actually very promising.

Something else?
Is there something else?