Apparatus for checking the user of a card in card-actuated machines

A system for checking the user of a card having recorded thereon coded information including a first number n and a second number, the former number expressing the number of times of use of said card, comprising:

• means for reading said first and second numbers;
• a first register for storing said first number n;
• a second register for storing said second number;
• means associated with said first register to produce values of the functions n+1, (n+1).sup.2 and ##EQU10## a third register for storing the value of the function n+1;
• a fourth register for storing the value of the function (n+1).sup.2 ;
• a fifth register for storing the value of the function ##EQU11## means operated by the user of said card to enter a third number;
• sixth register for storing said entered third number;
• an adder for adding said second number stored in said second register and said value of the function ##EQU12## stored in said fifth register to produce a fourth number;
• means for comparing said third and fourth number to recognize said user as the proper owner of said card when said third and fourth numbers coincide;
• a subtractor for subtracting the value of the function (n+1).sup.2 stored in said fourth register from said second number stored in said second register to produce a fifth number;
• and means for recording said fifth number and the value of said function n+1 stored in said third register on said card in place of said second and first numbers previously recorded thereon, respectively.

A system for checking the user of a card having recorded thereon coded information including a first number n and a second number, the former expressing the number of times of use of said card, comprising:

• means for reading said first and second numbers;
• a first register for storing said first number;
• a second register for storing said second number;
• means associated with said first register to produce a value of the function n+1 and a first random number R.sub.n+1 and a second random number ##EQU13## a third register for storing the value of the function n+1;
• a fourth register for storing the first random number R.sub.n+1 ;
• a fifth register for storing the second random number ##EQU14## means operated by the user of said card to enter a third number;
• a sixth register for storing said entered third number;
• an adder for adding said second number stored in said second register and said second random number ##EQU15## stored in said fifth register to produce a fourth number;
• means for comparing said third number and said fourth number to recognize said user as the proper owner of said card when said third and fourth numbers coincide;
• a subtractor for subtracting said first random number R.sub.n+1 stored in said fourth register from said second number stored in said second register to produce a fifth number;
• and means for recording said fifth number and the value of said function n+1 stored in said third register on said card in place of said second and first numbers previously recorded thereon, respectively.

A system for checking the user of a card having recorded thereon coded information including at least a first and second code, comprising:

• means for reading said codes;
• function generating means responsive to said first code read by said reading means to produce a third code, said third code having a predetermined mathematical relationship with said first code, said function generating means performing a predetermined mathematical operation so as to produce said third code;
• means operated by the user of said card to enter a card owner code;
• computational means responsive to said reading means and said function generating means for mathematically combining said second code with said third code, said computational means including coincidence checking means for comparing said entered card owner code with said mathematically combined second and third codes, said coincidence checking means supplying a control signal when said entered card owner code corresponds to said mathematically combined second and third codes;
• and code changing means responsive to said control signal supplied by said coincidence checking means for changing both said first and second codes on said card, said code changing means changing said first and second codes such that said mathematically combined second and third codes will correspond to said card owner code the next time said card is used in said system.

A card actuated system wherein each authorized user of said system is issued a card owner number and a card having recorded thereon at least a first code that is mathematically independent of said card owner number and a second code that is mathematically related to said card owner number by a predetermined mathematical quantity, said system comprising:

• means for reading said first and second codes from said card;
• means responsive to said first code read by said reading means to produce a third code, said third code having a predetermined mathematical relationship with said first code;
• means operated by the user of said card to enter said card owner number;
• computational means responsive to said reading means and said means for producing said third code for mathematically combining said second code with said third code, said computational means including coincidence checking means for comparing said entered card owner number with said mathematically combined second and third codes, said coincidence checking means supplying a control signal when said entered card owner number corresponds to said mathematically combined second and third codes;
• and code changing means responsive to said control signal supplied by said coincidence checking means for changing both said first and second codes on said card, said code changing means changing said first and second codes such that said mathematically combined second and third codes will correspond to said card owner number the next time said card is used in said system.

In a system operable by a card having recorded thereon at least a first and second code representative of a card owner code assigned to each card owner, the method of verifying that a user of said card has entered the correct card owner code comprising the steps of:

• reading said first and second codes on said card when said card is used in said system;
• generating a third code mathematically related to said first code;
• combining said second code with said third code by a predetermined mathematical operation;
• comparing said combined second and third code with said card owner code;
• and
• changing said first and second codes on said card when said combined second and third codes correspond to said card owner code.