USB Keystone. I believe I have enough room in the wall, if not, I'll use a small USB jumper cable.
I only plan to do this with the decryption key if possible, otherwise I put the whole thing inside wall.
(I included the names instead of links so you can choose your own vender. Amazon is faster, but eBay is cheaper, especially when buying in bulk.)
USB 3.0 Keystone SAMSUNG MUF-32AB/AM FIT Plus 32GB