Issues Restoring my Backup to my new iPhone 6 ! HELP

I recently got a new iPhone 6 and i wanted to restore all the content i had on my iPhone 5 to my new iPhone 6 ! I never had issues in the past, but for some reason this time when i clicked on "RESTORE FROM BACKUP", it kept asking me for a " password" that i have never set up in the past. Even after selecting a password, i cannot specifically select the backup i want to choose ( from my iPhone 5 ) without having an error message that says "WRONG PASSWORD", i have literally tried everything ... i don't know how to get all my stuff back onto my new phone without having this issue!