A password input and verification method is provided to prevent the
disclosing of the password from peeping. The method is easy to learn,
transparent to the users, and requires no hardware change and only minor
software modification. The method allows a user to enter a much longer
string of characters when he or she is asked for the password. The user
is then authenticated if the actual password is embedded as a whole
anywhere within the input string. The method also provides a mechanism
called prohibition key. A prohibition key is a pre-determined character
that, when present in the user input string, the user is not
authenticated regardless of whether the actual password is contained in
the input string or not.