Uh, why couldn't you just sign your authorized_keys file and post it somewhere public? Then you just literally download, verify signature, and 'import' it (overwrite or append to existing file).
You can clear sign an authorized_keys file with "gpg --clearsign <authorized_keys>", then just pass the resulting *.asc file to this script. It will verify the signature and 'import' it by copying it to ~/.ssh.
