Best backer option for Kerdi membrane

Hello y'all,

I am doing a shower tiled stall and am wondering what is the best backer to use with kerdi waterproofing membrane? With a little research I am leaning towards cement backer board. It seems that if there is an interior leak (inside the wall) well now that I think of it this is a major problem in itself....If there is a leak and I did use drywall then it will fall apart as where cement backer will not?

I guess my real question is what I started out with...What is the best backer for a shower installed with kerdi membrane?

thanks,

BV