Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
The problem might be, simply, that the Belkin router's Reset button has been pressed, and held down for too long, as long as 10 seconds or longer... this can reset *all* the settings and the setup back to factory defaults, erasing any password ***** Passphrase or WEP code you may have put onto the Belkin router and your wireless networking... and thus making the WEP code or Passphrase, as stored in your iDevices, invalid and incapable of logging on.
You would in that case, either have to
A. try to log on to the wireless network using no password, a blank for a password, no characters in the wireless password ***** entered on your iDevice
B. go into the Belkin router's admin setup utility, and enter the password (or preferably a new passphrase, since you have revealed it here) again etc., setting up the router once again.
This is admittedly a guess, but it is worth looking into, and is perhaps the simplest explanation for why your two iDevices (iPhone and iPad) suddenly no longer can log on to the Belkin router nor connect through it.