Terminal data encryption

• US 8,494,968 B2
• Filed: 06/18/2007
• Issued: 07/23/2013
• Est. Priority Date: 06/19/2006
• Status: Active Grant

• Current Assignee: Visa USA, Inc. (Visa, Inc.)
• Original Assignee: Visa USA, Inc. (Visa, Inc.)
• Inventors: Hammad, Ayman, Faith, Patrick
• Primary Examiner(s): KUCAB, JAMIE R
• Application Number:
  US11/764,351
• Publication Number:
  US 20080103982A1
• Time in Patent Office: 2,227 Days
• Field of Search: None
• US Class Current: 705/71
• CPC Class Codes: G06Q 20/085 involving remote charge determination or related payment systems
• CPC Class Codes: G06Q 20/105 involving programming of a portable memory device, e.g. IC cards, "electronic purses"
• CPC Class Codes: G06Q 20/20 Point-of-sale [POS] network systems
• CPC Class Codes: G06Q 20/204 comprising interface for record bearing medium or carrier for electronic funds transfer or payment credit
• CPC Class Codes: G06Q 20/367 involving electronic purses or money safes
• CPC Class Codes: G06Q 20/3672 initialising or reloading thereof
• CPC Class Codes: G06Q 20/3674 involving authentication
• CPC Class Codes: G06Q 20/382 insuring higher security of transaction
• CPC Class Codes: G06Q 20/3821 Electronic credentials
• CPC Class Codes: G06Q 20/3829 involving key management
• CPC Class Codes: G06Q 20/385 using an alias or single-use codes
• CPC Class Codes: G06Q 20/40 Authorisation, e.g. identification of payer or payee, verification of customer or shop credentials; Review and approval of payers, e.g. check credit lines or negative lists
• CPC Class Codes: G06Q 20/401 Transaction verification
• CPC Class Codes: G06Q 2220/00 Business processing using cryptography postage metering system using cryptography G06Q2250/05
• CPC Class Codes: G06Q 30/06 Buying, selling or leasing transactions
• CPC Class Codes: G06Q 40/00 Finance; Insurance; Tax strategies; Processing of corporate or income taxes
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 9/3271 using challenge-response

Abstract

A method is disclosed. The method includes generating an initial key after interacting with an access device, storing the initial key at a key storage location, altering the initial key with a public key to form an altered key, and sending the altered key to a server computer along with an identifier for the access device. The altered key is changed to the initial key at the server computer and is stored with the identifier in a database in operative communication with the server computer. The initial keys that are stored at the key storage location and in the database are used to alter and restore transaction data associated with multiple financial transactions that are conducted using the access device.

Claims

1. A method comprising:

generating at an access device an initial key, wherein the step of generating the initial key is based on a first interaction between the access device and a first portable consumer device, and wherein the access device includes a point of sale device;

sending the initial key to a key storage location, wherein the initial key is sent by the access device;

altering the initial key with a public key to form an altered key, wherein the initial key is altered by the access device;

sending the altered key from the access device to a server computer along with an identifier for the access device; and

altering, with the initial key that is stored at the key storage location, transaction data associated with a plurality of financial transactions that are conducted using the access device,

wherein the altered key has a form capable of being changed to the initial key at the server computer.

2. The method of claim 1 wherein the initial key is a symmetric key and wherein the key storage location is in the access device.

3. The method of claim 1 further comprising:

altering the identifier to form an altered identifier; and

sending the altered identifier to the server computer,

wherein sending the altered key and the altered identifier data to a server computer is part of a special initialization transaction that is different from a transaction associated with a purchase.

4. The method of claim 1 wherein the first interaction comprises using the first portable consumer device to interact with the access device in a financial transaction, and wherein altering comprises encrypting.

5. The method of claim 4 wherein the encrypting comprises performing an encryption process, the access device being capable of performing the encryption process.

6. The method of claim 5 wherein the encryption process comprises elliptical curve cryptography.

7. The method of claim 1 wherein a host computer is coupled to the access device.

8. The method of claim 7 wherein the public key is stored in the host computer.

9. The method of claim 7 wherein the host computer generates the initial key.

10. The method of claim 7 wherein the host computer performs the altering.

11. The method of claim 1, wherein the altering of the transaction data associated with the plurality of financial transactions comprises:

receiving, with the access device, single transaction data associated with one of the plurality of financial transactions, the single transaction data including a plurality of track data elements read from a second portable consumer device;

altering, with the access device, a first track data element of the plurality of track data elements to form an altered track data element at least in part by encrypting the first track data element with the initial key;

altering, with the access device, the single transaction data to form altered transaction data at least in part by placing the altered track data element in a second track data element of the single transaction data such that the first track data element of the transaction data is blank; and

providing, with the access device, the altered transaction data such that the altered transaction data passes through at least one intermediate location before arriving at its destination.

12. The method of claim 11 wherein the second track data element further includes a fast Fourier transform of the plurality of track data elements read from the second portable consumer device.

13. A non-transitory computer readable medium having thereon computer-executable instructions that, when executed by one or more computers, cause the one or more computers to collectively, at least:

generate at an access device an initial key, wherein the step of generating the initial key occurs after the access device interacts with a first portable consumer device, and wherein the access device includes a point of sale device;

send the initial key to a key storage location, wherein the initial key is sent by the access device;

alter the initial key with a public key to form an altered key, wherein the initial key is altered by the access device; and

send the altered key from the access device to a server computer along with an identifier for the access device; and

alter, with the initial key that is stored at the key storage location, transaction data associated with multiple financial transactions that are conducted using the access device and that occur after the access device interacts with the first portable consumer device,

wherein the multiple financial transactions include at least one interaction between the access device and at least one portable consumer device that is different from the first portable consumer device.

14. The computer readable medium of claim 13 wherein the computer-executable instructions further cause the one or more computers to store the altered key in the key storage location.

15. The computer readable medium of claim 13 wherein the first portable consumer device is a payment card, and wherein the access device comprises a point of sale device.

16. An access device comprising the computer readable medium of claim 15.

17. The access device of claim 16 wherein the access device is a point of sale terminal.

18. The computer readable medium of claim 13 wherein the database includes a lookup table which stores the initial key and the identifier.

19. The computer readable medium of claim 13 wherein the code for altering comprises code for encrypting.

20. The computer readable medium of claim 19 wherein the code for encrypting comprises code for performing an encryption process, the access device being capable of performing the encryption process.

21. The computer readable medium of claim 20 wherein the encryption process comprises elliptical curve cryptography.

22. The computer readable medium of claim 13 wherein the computer-executable instructions further cause the one or more computers to, at least:

alter the identifier to form an altered identifier; and

send the altered identifier to the server computer,

wherein sending the altered key and the altered identifier data to a server computer is part of a special initialization transaction that is different from a transaction associated with a purchase.

23. The computer readable medium of claim 13 wherein the initial key is a symmetric key, wherein the key storage location is in the access device, and wherein the generating of the initial key, the altering of the initial key, and the sending of the altered key are conducted when the access device first communicates with the server computer.