A self-authenticating check authorization system and method includes a check
that
has standard bank and account information printed on the MICR line, as well as
a one-way hash value that is computed based on the standard bank and account information
as well as a personal identification code of a customer. The scanned MICR line
data is provided to a check verifier, which also receives the personal identification
code from the customer. The check verifier performs a hashing algorithm on the
received data, and compares the computed hash value to a hash value obtained from
the scanned MICR line data. If there is a match, the check is verified; if not,
the check is not verified.