Abstract: A proceeds processing apparatus has an apparatus body, and a keyboard and a card reader provided on the apparatus body for entering first data indicative of the contents of a transaction. An operation control is accommodated in the apparatus body for executing data processing including proceeds processing by performing arithmetic operations with inputted data. A display and a printer are provided on the apparatus body and interconnected to the operation control for outputting the result of data processing. A customer-oriented input unit has a keyboard and a control for inputting second data for determining whether or not the first data entered are agreed to. An interface and a cable electrically interconnect the keyboard and the control to the operation control. The operation control determinines, in response to the second data fed from the keyboard and the control, whether or not the first data are agreed to on the basis of the second data and feeds a result of decision to the display and printer.

Abstract: The present invention relates to a secret identification number checking system for comparing a secret identification number stored in a magnetic card (11) and a secret identification number entered by the bearer of the magnetic card. Data to enable the comparison is stored in a card medium (13), and the card medium (13) and a transaction machine (17) mutually authenticate each other. When if both the card medium (13) and the transaction machine (17) are legitimate, the card medium (13) sends the data to the transaction machine (17) to permit the secret identification number stored in the magnetic card (11) to be compared with the secret identification number entered by the bearer of the magnetic card. The secret identification number checking system thus improves the security of transactions.