Trying to set up SSH with shared key, but the server is not recognizing the device's key

I'm running an Amazon Fire HD 7 first gen, with CyanogenMod 11 on it. Here are my system settings since they're required on Reddit: I'm trying to set up SSH with a shared key on CyanogenMod. Normally, it's very easy to connect to my server, but I'm having difficulty setting this up. I did ssh-keygen -t rsa -b 4096 on my Kindle as root, because the user didn't have access to the folders (why is this, by the way? Why can't the user even see the data folder?). I put the key in the default folder with the default file name, which was /data/.ssh/id_rsa. Then I copied id_rsa.pub over to the authorized_keys file on my server, where all the other keys that work are. I restarted the SSH server, but it keeps telling me the public key failed. I ran SSh with the -vv option, and it tells me the same thing, that the keys are not matching with the error message Permission denied (publickey). What do I need to do to get the server to recognize the key?