1. An authenticating method for verifying password input by a user, comprising the following steps: (1) corresponding to a known character set contained in a predefined password, defining a candidate character set constructed by a plurality of characters, said known character set being a subset of the candidate character set; (2) randomly distributing all the characters of the candidate character set into a plurality of candidate character subsets such that at least one candidate character subset includes two or more characters, and correspondingly distributing and displaying characters of the candidate character subsets in a plurality of interactive regions respectively; and (3) receiving from the user instructions regarding selection of specific interactive regions based on the characters of the known character sets, checking one by one whether each character of the known character set belongs to the candidate character subsets corresponding to the specific interactive regions currently selected by the user, and confirming successful authentication and outputting signals indicating successful authentication when all the characters of the known character set belong to the candidate character subsets corresponding to the specific interactive regions currently selected by the user.