You can use the hhstore command to store access authorisation for your account on a remote host.
Whenever you transfer a file to or from this host the access authorisation that you have stored is automatically used by hhcp to authorise the file transfer.
hhstore -a festival transfer authorization: helper transfer password: password
This stores authorisation for transfers to and from the user's account on the host "festival", on which their registered username is "helper". Note that the password is not displayed.
The -a option ensures that you are only prompted for your username and password.