The present invention constitutes a process and an apparatus intended to prevent the unauthorized use of a magnetic card, such as a credit card or similar. In the attempt to solve this problem various devices have been suggested which, actually, are based exclusively on two distinct types of strategies.

The first one consists of condensing all the necessary information in a central computer and the second one on distributing part of the information (lists of the cancelled cards) to each organization which uses the system of credit cards. The solutions which utilize the exchange of information with a central computer suffer from all the shortcomings which characterize this technique, such as congestion of transmission lines, access time, inactive computer and high cost of installation and maintenance.

The solutions which use distributed information can be also grouped in two categories. In the first one, the list of invalid cards is internally recorded in the device. The methods of recording vary depending on the patent, from magnetic disks, diskets or even through direct entry via keyboard. In the second category, the checking of cancelled cards is done by visual reading of lists which, besides causing embarrassment to the clients, is greatly subject to error (either in the checking or in the concept), not considering the high cost of data collection, printing and waste of outdated printed material.

As a result, in both categories of the second type of strategy one faces the

problem of distribution and periodic updating of the means used to check the disabled cards. Another disadvantage of that type of strategy is the time lag between the appearance of a newly cancelled card and its recognition by the stores, which often is not short enough to prevent utilization of the card, since the change in the records is not instantaneous.

Independently of the type of strategy which is adopted, the great majority of the patents claimed so far have in common an internal device for checking the password in the card and the password keyed in by the user.

The present invention creates a third strategy which eliminates the above - mentioned shortcomings, as well as those of other systems based on the state of the technique.

Summary of the Invention

The "Card Validator" utilizes telecommunication means, in which an internal device receives the information of interest to the transmitting stations and records it in the memory of the device. This information may be numerical or alphanumerical, so that the device can store all the necessary information on a card and also a complete listing of the cancelled cards. This technique permits the instantaneous updating of any data relating to the cards, despite the fact that the device is "off-line". In this way, the Card Validation not only has a device to check the password but is also capable of verifying whether or not the card in use has been cancelled. It is therefore an apparatus which both authenticates the user and validates the card, thereby elimininating the need of printed lists of cancelled cards.

The "Card Validator" was designed to offer maximum ease of operation and the advantage of being a portable unit because of its small size. In places like restaurants, for example, it can be brought to the user, who can operate it at his own table.

Brief Description of the Drawings Figure 1 is a flowchart of the system of operation of the "Card Validator" in accordance with the present invention.

Figure 2 is a front view of the apparatus in accordance with the present invention.

Figure 3 is a front and side view of the apparatus in accordance with the present invention.

Detailed Description of Preferred Modes The "Card Validator" is made up of: A Magnetic Card Reader (1) which reads the password and the card number

(recorded on the magnetic strip). Other information can be added, as desired by the credit institution.

Receiving Unit (2) which acquires the data about cancelled cards which are transmitted by electromagnetic waves through transmitting stations throughout the state.

Memory Unit (3) where the data received by the Receiving Unit are recorded.

Alphanumeric Keyboard (6) made up of 10 numerical keys and 2 control keys (enter and delete). Microprocessor (4) which carries out all the necessary procedure to evaluate the operation. This procedure compares the password (keyed in and read), checks the existence of a given card in the cancelled list and either actuates the flashing lights or shows a message in the display, depending on the type of apparatus. Light Indicators or Display. The operational procedure and the final evaluation are shown to the user in two different ways, according to the mode for which the apparatus was built. Thus, the "Card Validator" can have a small light

emitting diode screen in which messages will appear, or it can have a group of three luminous indicators. In the model having the luminous indicators, these are located in the upper part of the apparatus (7), (7) and (7), and show the colors Yellow, Green, and Red, which indicate the correct reading, the validity and invalidity of the card, respectively. In the model which has the Display (8), those indications are in the form of a written message. In either of the two options there are in addition two luminous indicators in the lower part of the apparatus which signal the need for charging the internal batteries and an error in the data transmitted by the stations. Battery Charger (5) which continuously recharges the internal battery of the apparatus and ensures the independent operation of the device. The existence of this platform makes the "Card Validator" a portable apparatus (9). Description of Operation

As described before, the "Card Validator" (CV) can be had in two models. The first one with a liquid crystal display and the second one with three luminous indicators (Yellow, Green, and Red) in place of the display. In this report, when we refer to display we shall be talking about the first one, and when we refer to luminous indicators or lamps we shall be talking about the second model.

When we turn on the on/off switch, the three indicator lamps in the panel will light up simultaneously or the display will be full for a short time, after which the display and the lamps will go off. After that, the CV is ready to start operating.

When it is being checked, the card must be run through the slot with the magnetic band in is lower part and facing the user.

At the end of this procedure the CV will have read the data on the card and will light the yellow luminous indicator, or it will send a message to the display that the reading was satisfactory and the password can be keyed in

After the user keys in the password, pressing the ENTER key will start the

checking of the password and of the validity of the card.

The lumious green indicator in the panel will light up if the password is correct, and it will stay lit for a short time, after which it will go off together with the yellow indicator, signaling that the password is correct and that the card is not cancelled, or the display will show a message that the card is valid for use.

If the password keyed in by the user is incorrect, the display will show a message to that effect. The user will have two additional chances to key in the password. Each new chance starts when the key delete is pressed, which causes the CV to delete the password error message and is ready for the password to be keyed in again. In the model with luminous indicators, in a similar case, the red and the yellow lights will light up and the procedure to re-enter the password is exactly as described above. If the green light comes on after re-entering the password, the use of the card is valid. In the CV with the display, the use of the card will be validated by a message. If the password is keyed in correctly but the card is in the cancelled list, the red light will come on (yellow off), or a message will indicate this condition in the display.

If the luminous indicator signaling "transmission error" comes on, the store must contact the credit institution so that this fact may be communicated to the transmission central and a new transmission can take place.

If the battery charge indicator comes on, the internal battery of the CV needs recharging. For this purpose the apparatus must be left on the recharging base, which must be connected to the electrical power supply.

The "Card Validator" is made up of the blocks shown in Fig. 1. The blocks "Interface with Liquid Crystal Display" and "Alphanumerical Liquid Crystal Display" are present only in the model of the "Validator" with display.

The bar which interconnects the various blocks concentrates the flow of

information from the microprocessor to the blocks and from the blocks to the microprocessor.

Microprocessor (4) controls the whole process of validation of the magnetic card through interface with the other blocks. The memory units (3) store the control program executed by the mcroprocessor and the data on cancelled cards.

The radio receiver (2) receives through the antenna the data sent by the transmitting station on the invalid cards.

The interface with the radio receiver makes the receiver signal compatible with the interconnecting bus.

The card reader (1) acquires the data recorded on the magnetic card when this card is run through the slot of the reader.

The interface with the card reader makes the reader signal compatible with the interconnecting bus. The interface with the Liquid Crystal Display makes the signals for the liquid criystal display compatible with the interconnecting bar.

The luminous indicators (7) are LEDs which show the condition of the CV.

The interface with the luminous indicators makes the signals to the indicators compatible with the interconnecting bus. The keyboard (6) receives the data keyed in by the owner of the card and by the "validator" operator.

The interface with the keyboard makes the keyboard signals compatible with the interconnecting bus.

The power source (5) generates the necessary tensions for the operation of the "validator" unit and it can receive energy from the external power network or from the battery.

The battery (5) protects the data in the memory units during failure of the

external power supply.

The operation of the group of blocks is described below:

As the magnetic card is run through the card reader, the card reader sends through its interface with the interconnecting bus a stop order to the microprocessor which then executes the part of the program stored in the memory units which handles the reception of the data sent by the reader.

The reader sends all the data stored in the magnetic band of the card to the microprocessor which cheks the integrity of the data and stores them in the memory unit. The microprocessor then executes the program which waits for the data originating from the keyboard. After the password is keyed in by the card owner, the microprocessor receives these data through its interface with the keyboard and interconnecting bus, and goes on to execute the cryptographic algorithim of verification of the password by comparing them with those stored in the memory, originating from the card reader. If the password does not check with the data on the card, the microprocessor sends a message to the alphanumerical liquid crystal display through the interface with the liquid crystal display and interconnecting bus.

If the password does check with the data in the memory unit, the microprocessor goes on to execute the search program in the memory units to see if the card is in the list of cancelled cards. If the card is in the list the microprocessor displays the message and returns to the mode of waiting for the entry of new data.

If the password checks and the card is not in the list of cancellations, the microprocessor sends a card release message and returns to the mode of waiting for the entry of new data.

If the CV model does not use the alphanumerical liquid crystal display, the indicators will be actuated by the microprocessor through the interface with the

indicators and the interconnecting bus.

When the transmitting station sends new data on cancelled cards the radio receiver will send a stop order to the microprocessor which goes on to execute a program to update the cancelled cards stored in the memory unit on the basis of the new list sent by the transmitting station.

The program which receives information on cancelled cards will be executed concurrently with the program of checking and validation of the cards whenever necessary.

During the operation to update the list of cancellations, if the program detects any invalid data or transmission error, the microprocessor will show a message in the liquid crystal display or luminous indicator which will identify the problem.

From time to time the microprocessor will execute a program to check all functions of the "validator" and will show a message in the event that any problem has been detected.

In case of failure of the external power supply, the power source will use the batteries to feed the data of the cancelled cards to the memory units, so that the data will be preserved until the external power returns.

During the time that the power is supplied by the external electrical network, the power source provides the tension to all the CV devices and also recharges the battery.