What Kind Of Paint Can I Use On A Basement Shower Floor?

Hello. Thanks for reading this question. I have a basement bathroom with a shower, sink, and toilet. The shower is surrounded on three sides by concrete blocks walls and is painted with, I think, Sunny Dri Cement Paint. The floor of the shower is not painted. It was at one time painted with, I have been told, porcelain paint by my father - who died many years ago. I have asked some local home improvement centers where I can purchase porcelain paint. All I get is that they can sell me touch up paint. Is Porcelain Paint a good choice for a basement bathroom shower floor? If not, what else could I use? I have been told that I would need to etch the concrete floor with Muratic Acid before applying this so called Porcelain Paint. By the way, we have mildew in that shower, which we will be cleaning off and repainting with Sunny Dri whenever we get some non rainy days here in Western Pennsylvania. I await your thoughts on this matter.
Thanks.