It would be more user friendly to have "remember secret phrase for this session" checked by default on login so the users won't have to enter the secret phrase sending a message/bid e each time.
If that isn't secure, maybe there could be a 4 digit pin number that the users could use instead of entering the whole password again. The app should disable the pin number and require full password after 5 unsuccessful pin numbers are used.
So the login screen would look like this:
"Remember password during this session" checked by default
Under it, a text field that would say "pin number for the session" (only 4 numbers allowed)
Good Idea.