connect yourself to the box and cd /home/files/;
ls -ald poa10
the output should look like:
drwxr-xr-x ...
the first set of rwx is for the owner, the second for the group and the third for all others...
rwx is read write execute I let you guess the rest...
I usually give software stuff a GID (group ID) and include the athorized uid to that group and so change the directory perms to 775 or
drwxrwxr-x or even drwxrwx--x...
you could even do
drwxrwsr-x which would force whatever file is copied there to inherit the GID...

ssh without passwd is per user auth with strongkey auth with public private key exchange
the best would be for you to read the man pages or do some search to see possible confgurations and "HOWTOS"...

All the best