Transaction signature for offline payment processing system

摘要

Preventing fraud during an offline transaction by encoding a randomly-generated card verification code onto a smart card. The verification code is transmitted to a contactless device during each transaction, wherein it is cross-referenced with the account number to ensure presence of the card. Also, every transaction record is signed by an access key resident on the contactless device and certified by a signing key resident on a remote system. Funds may be deposited onto the card when the contactless device creates a deposit request, signs the request using an access key and transmits it to the remote system, which in turn processes the request and certifies it with a signing key. Funds may be withdrawn when the contactless device creates a withdrawal record and signs it using an access key. The remote system verifies the signatures and certifies the records using a signing key when the records are later transmitted.

主权项

1. A computer-implemented method for processing a withdrawals of funds during offline payment processing of purchases, comprising:
starting a payment session by a mobile communication device; establishing, by the mobile communication device, a network connection with a computer managing smart card device accounts; receiving, by the mobile communication device, a session access key from, the computer managing the smart card device accounts; establishing, by the mobile communication device, a communication channel with a smart card device while the mobile communication device is without a network connection to the computer managing the smart card device accounts; receiving, by the mobile communication device and from the smart card device, a smart card device transaction history comprising a listing of previous deposit transactions and a listing of previous withdrawal transactions; calculating, by the mobile communication device, an amount of previous withdrawals using the listing of previous withdrawal transactions and an amount of previous deposits using the listing of previous deposit transactions; authorizing, by the mobile communication device and without a network connection to the computer managing the smart card device accounts, an offline debit transaction by determining that a current transaction amount is less than or equal to a difference between the amount of previous deposits and the amount of the previous withdrawals; creating, by the mobile communication device, an offline withdrawal transaction record subtracting the current transaction amount from a smart card device account balance; signing, by the mobile communication device, the withdrawal transaction record using the session access key; and writing, by the mobile communication device, the signed withdrawal transaction record to the smart card device transaction history, the signed withdrawal transaction record indicating the current transaction amount debited from the smart card device account balance and the session access key signature.