A device is provided that includes a monetary instrument having a surface, and a magnetic ink character recognition (MICR) line coupled to that surface. The MICR line includes an ABA number, a customer account number, and a one-way hash value. The one-way hash value is output from a hashing process using input including the ABA number, the customer account number, together with a personal identification code and a key that are not included on the MICR line. A method is also provided that authenticates a monetary instrument by comparing a computed one-way hash value with a one-way hash value that is located in the MICR line of the monetary instrument. At the point-of-sale, the MICR line data is scanned and the personal identification code obtained from the customer. The scanned data and the personal identification code are transmitted to a check verifier that provides a check verification status.