Authenticating a payment card

A computer program product for authenticating a payment card, the computer program product comprising a computer readable storage medium having program instructions stored on the computer readable storage medium, wherein the computer readable storage medium is not a transitory signal per se, and the program instructions are executed by a central processing unit (CPU) of a computer system to cause the computer system to perform a method comprising the steps of:

• the computer system reading information from the payment card being used for a purchase, the information including an identifier of the payment card, data on a chip included in the payment card, data encoded in braille cells on the payment card, and data encoded in markings included in the payment card;
• the computer system decrypting the information read from the payment card using a decryption key included in the data encoded in the markings;
• in response to a determination that the decryption key is a correct key and based on the decrypted information, the computer system sending to a payment system (i) a hash read from the chip included in the payment card, (ii) the identifier of the payment card, (iii) a first security code printed on the payment card, and (iv) a second security code included in the data encoded in the braille cells;
• the computer system receiving from the payment system a hash of an (n+1)-th block of a blockchain ledger in response to the payment system (i) validating the hash sent to the payment system as matching a hash of an n-th block of the blockchain ledger, (ii) validating the identifier of the payment card, (iii) validating the first security code, (iv) validating the second security code included in the data encoded in the braille cells, and (v) generating the hash of the (n+1)-th block;
• the computer system recording the hash of the (n+1)-th block in the chip included in the payment card as an update of the hash that was read from the chip;
• and
• the computer system sending data about the purchase and the hash of the (n+1)-th block to the payment system, which causes the payment system to (i) validate the hash of the (n+1)-th block which confirms the hash of the (n+1)-th block is recorded in the chip and (ii) add the data about the purchase as a transaction into the (n+1)-th block.

A computer system comprising:

• a central processing unit (CPU);
• a memory coupled to the CPU;
• and
• a computer readable storage device coupled to the CPU, the computer readable storage device containing instructions that are executed by the CPU via the memory to implement a method of authenticating a payment card, the method comprising the steps of:
• the computer system reading information from the payment card being used for a purchase, the information including an identifier of the payment card, data on a chip included in the payment card, data encoded in braille cells on the payment card, and data encoded in markings included in the payment card;
• the computer system decrypting the information read from the payment card using a decryption key included in the data encoded in the markings;
• in response to a determination that the decryption key is a correct key and based on the decrypted information, the computer system sending to a payment system (i) a hash read from the chip included in the payment card, (ii) the identifier of the payment card, (iii) a first security code printed on the payment card, and (iv) a second security code included in the data encoded in the braille cells;
• the computer system receiving from the payment system a hash of an (n+1)-th block of a blockchain ledger in response to the payment system (i) validating the hash sent to the payment system as matching a hash of an n-th block of the blockchain ledger, (ii) validating the identifier of the payment card, (iii) validating the first security code, (iv) validating the second security code included in the data encoded in the braille cells, and (v) generating the hash of the (n+1)-th block;
• the computer system recording the hash of the (n+1)-th block in the chip included in the payment card as an update of the hash that was read from the chip;
• and
• the computer system sending data about the purchase and the hash of the (n+1)-th block to the payment system, which causes the payment system to (i) validate the hash of the (n+1)-th block which confirms the hash of the (n+1)-th block is recorded in the chip and (ii) add the data about the purchase as a transaction into the (n+1)-th block.

A method of authenticating a payment card, the method comprising the steps of:

• a computer receiving information from the payment card being used for a purchase by a user and sending the information to a payment system, the information including an identifier of the payment card, a first security code printed on the payment card, a second security code encoded in braille cells on the payment card, and an expiration date of the payment card;
• the computer receiving a hash via an entry in a web form and sending the received hash to the payment system, the entry being a copy of a hash of an n-th block of a blockchain ledger sent by the payment system to a mobile device of the user in response to the payment system (i) validating the identifier of the payment card, (ii) validating the first security code, (iii) validating the second security code encoded in the braille cells, and (iv) retrieving the hash of the n-th block from the blockchain ledger by determining that the n-th block is associated with the identifier of the payment card;
• the computer receiving from the payment system a hash of an (n+1)-th block of the blockchain ledger in response to the payment system (i) validating the hash sent to the payment system as matching a hash of the n-th block of the blockchain ledger and (ii) generating the hash of the (n+1)-th block;
• and
• the computer sending data about the purchase and the hash of the (n+1)-th block to the payment system, which causes the payment system to (i) validate the hash of the (n+1)-th block and (ii) add the data about the purchase as a transaction into the (n+1)-th block.

A computer program product for authenticating a payment card, the computer program product comprising a computer readable storage medium having program instructions stored on the computer readable storage medium, wherein the computer readable storage medium is not a transitory signal per se, and the program instructions are executed by a central processing unit (CPU) of a computer system to cause the computer system to perform a method comprising the steps of:

• the computer system receiving information from the payment card being used for a purchase by a user and sending the information to a payment system, the information including an identifier of the payment card, a first security code printed on the payment card, a second security code encoded in braille cells on the payment card, and an expiration date of the payment card;
• the computer system receiving a hash via an entry in a web form and sending the received hash to the payment system, the entry being a copy of a hash of an n-th block of a blockchain ledger sent by the payment system to a mobile device of the user in response to the payment system (i) validating the identifier of the payment card, (ii) validating the first security code, (iii) validating the second security code encoded in the braille cells, and (iv) retrieving the hash of the n-th block from the blockchain ledger by determining that the n-th block is associated with the identifier of the payment card;
• the computer system receiving from the payment system a hash of an (n+1)-th block of the blockchain ledger in response to the payment system (i) validating the hash sent to the payment system as matching a hash of the n-th block of the blockchain ledger and (ii) generating the hash of the (n+1)-th block;
• and
• the computer system sending data about the purchase and the hash of the (n+1)-th block to the payment system, which causes the payment system to (i) validate the hash of the (n+1)-th block and (ii) add the data about the purchase as a transaction into the (n+1)-th block.