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 and a key. 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.