System for identifying authorized use of credit cards

Abstract

A credit card system for providing verification of authority of a credit card bearer to use the credit card for a credit transaction. Initial authorization of card use is given to the authorized user upon selection by the user of one of a set of supplemental characters appearing on the card as the authorized user's private identifier. Presentation of the card at a point of sale initiates a check of this private identifier against a supplemental character identified by the presenter of the card as his/her private identifier.

What is claimed is: 
     
       1. A system for indicating a bearer of a credit card as its authorized cardholder, the system comprising: a plurality of credit cards issued to cardholders, each credit card .[.being embossed with.]. having a first set of .[.raised.]. characters indicating an account number and .Iadd.having .Iaddend.a supplemental set of .[.raised.]. characters which have a one to one correspondence with each .[.digit.]. .Iadd.character .Iaddend.of the account number;   an account data file for each account number comprising identification data with respect to a cardholder, the identification data being also known or determinable by the cardholder, the account number, a cardholder identification code comprising the account number, a character selected by the cardholder from the set of supplemental characters and the .[.digit.]. .Iadd.character .Iaddend.in the account number corresponding to the selected character; and   means for matching the account number appearing on a presented credit card with its respective account data file and for comparing a supplemental character identified from the presented credit card by the bearer with the selected supplemental character appearing in the cardholder identification code;   whereby a match indicates the bearer as being the cardholder and lack of a match indicates the bearer is not the cardholder.   
     
     
       2. The system as defined in claim 1, wherein the matching and comparing means further comprises: data processing means for maintaining the plurality of account data files, for calling account data files in response to input of cardholder account numbers, for determining matches between a supplemental character identified by the presenter with the selected supplemental character, and for generating approval or disapproval indications as a result thereof;   a data terminal at the point of presentation of a credit card for relaying credit card generated and presenter generated data to the data processing means and for displaying approval or disapproval indications; and   a communications link between the data terminal and the data processing means.   
     
     
       3. The system as defined in claim 2, wherein the credit card comprises: .[.raised.]. characters indicating a name of the cardholder;   .[.raised.]. characters indicating the expiration date of the card; and   a machine-readable representation of the cardholder account number.   
     
     
       4. The system as defined in claim 3, wherein the data terminal further comprises means for reading and transmitting the machine-readable representation of the cardholder account number. 
     
     
       5. The system as defined in claim 4, further comprising sleeve means adapted to be fitted over the credit card to alter the machine readout of its respective account number to indicate the .[.digit.]. .Iadd.character .Iaddend.corresponding to a supplemental character identified by the presenter. 
     
     
       6. The system as defined in claim 2, the system further comprising: means for changing the selected supplemental character in the account data file at the behest of the cardholder upon identification by the cardholder of selected data in the account data file.   
     
     
       7. The system as defined in claim 1, wherein the set of supplemental characters is selected at random from a set of characters. 
     
     
       8. The system as defined in claim 1, further comprising: a charge slip having a plurality of sheets which can be marked by the .[.raised.]. characters of a credit card, any one of which sheets can be separately marked upon by the credit card bearer to identify a supplemental character.   
     
     
       9. A method of verifying a bearer of a credit card as its authorized user, the method comprising the steps of: issuing a credit card to an authorized user, .[.embossed with.]. .Iadd.having .Iaddend.a first set of .[.raised.]. characters indicating an account number and a second set of .[.raised.]. supplemental characters, each of the supplemental characters being in one to one correspondence with a particular .[.digit.]. .Iadd.character .Iaddend.of the account number;   requiring the authorized user to select at least a first supplemental character from the second set of .[.raised.]. characters before the allowing the credit card to be used for credit transactions;   retaining in an account data file for each issued credit card, identification data with respect to the authorized user, the account number and a user identification number formed from the account number, the selected supplemental character and the corresponding .[.digit.]. .Iadd.character .Iaddend.supplemental character from the account number;   employing the credit card to print the account number and the supplemental characters .[.or.]. .Iadd.on .Iaddend.a charge slip including at least a customer copy of the charge slip;   matching the account number appearing upon the credit card with its respective account number file upon presentation of the credit card for use;   having the bearer of the presented card .[.mark.]. .Iadd.indicate .Iaddend.a supplemental character .[.on the customer copy of the charge slip.].   comparing the .[.marked.]. .Iadd.indicated .Iaddend.supplemental character to the selected supplemental character in the account data file; and   approving the transaction if and only if the indicated supplemental character matches the identified supplemental character.   
     
     
       10. A credit card system which comprises: a credit card with a pair of primarily flat faces;   a first set of .[.raised.]. .Iadd.characters .Iaddend.on the first face of the credit card indicating an account identification code;   a machine-readable representation of the characters of the account identification code;   a supplemental set of .[.raised.]. characters on the credit card, each character of the supplemental set having a correspondence to a different first set character; and   a sleeve fitted over the credit card to alter the machine-readable representation of the cardholder account code upon alignment of the sleeve with a character from supplemental set character identified by a bearer of the credit card.