Concrete floor paint should work on the floor, but not sure it will do much for the humidity. If your basement is really humid and ever gets water seepage, you have a drainage issue you need to tackle, rather than looking for a quick patch like new paint.
Judy, you need to correct your moisture issue before you do any kind of painting. Do not rely on water proofing paint on walls that will only trap moisture behind the cement walls and cause damage that you cannot see. There are several topics on correct methods of water proofing here so I will not get into this on this post.
Once your done and your sure that you have corrected the water and dampness issues you can paint the floor with any porch and floor paint that you like. Many will tell you right on the can if it can be used on cement. The paint has no idea if your in a basement or your back porch so if it say good on cement, its good on cement.
But because doing proper water control and water proofing, there is a difference, may require you to dig into the cement floor of the house. There is no sense painting it nice only to dig it up and have to start all over again.
Humidity is airborne moisture
That is only indirectly connected to surfaces and painting.
Can you describe your situation in greater detail?
There are a great many different kinds of porch and floor paints. Some of the best are urethanes that are moisture cured, taking moisture from the air for the chemical reaction that cures them hard.
But if you have dampness IN the concrete, that is a a separate issue that needs to be corrected. Never paint a wet surface.
There isn't a drainage issue as that was taken care of during construction. There isn't any standing water, nor a damp feeling on the walls or floor. We run a dehumidifier in the summer only for those days when the AC isn't running.
Thanks for all your suggestions!
Not recommended. Your best bet will be to use a floor sealer.
don't forget that paint isn't suitable due to its poor resistance to pedestrian traffic - coatings are acceptable however they are not as easily applied