Payment system

Patent metadata

Field	Value
Publication number	US-11694199-B2
Application number	US-202117358837-A
Country	US
Kind code	B2
Filing date	Jun 25, 2021
Priority date	Apr 5, 2011
Publication date	Jul 4, 2023
Grant date	Jul 4, 2023

Abstract

Methods, apparatus and computer software are provided for authorizing an EMV transaction between a user device and a point of sale terminal, particularly, but not exclusively, in situations where a secure element is not made available for the deployment of a payment application on the user device. The payment application is instead deployed to a processing environment that is outside of any secure element on the user device. An ICC Master Key corresponding to the payment application is held by a trusted authority, such as the issuing bank. The trusted authority is adapted generate time-limited session keys on the basis of the ICC Master Key and distribute session keys to the payment application. Receipt of a session key by the payment application enables the payment application to conduct an EMV payment transaction. The session key is used to authorize a single EMV payment transaction.

First claim

What is claimed is:

1. A user device for conducting a payment transaction with a point-of-sale terminal, the payment transaction being one that is authorized as part of the payment transaction by an issuing bank, wherein the issuing bank holds data indicative of an ICC Master Key, the user device comprising a payment application, the payment application having a first operative state wherein the payment application is enabled to conduct the payment transaction, and a second operative state, different to the first operative state, and wherein the payment application is responsive to receipt of a session key, different from the ICC Master Key, generated by the issuing bank on the basis of the ICC Master Key, whereby to be configured into the first operative state and thereafter is configured to perform an authorization process, the authorization process comprising the steps of:
receiving a request for an application cryptogram;
generating the application cryptogram on the basis of the received session key; and
transmitting the generated application cryptogram to the point-of-sale terminal for verification thereof by the issuing bank and authorization of the payment transaction.

2. The user device according to claim 1 comprising:
a first processing portion; and
a second processing portion,
wherein the first processing portion comprises a first application environment within a secure element and the second processing portion comprises a second application environment external to the secure element, wherein the second processing portion comprises the payment application.

3. A computer readable medium comprising a computer program, or a suite of computer programs, which, when executed on a user device, causes the user device to perform an payment transaction, the payment transaction being one that is authorized as part of the payment transaction by an issuing bank, wherein the issuing bank holds data indicative of an ICC Master Key and generates a session key, different from the ICC Master Key, on the basis of the ICC Master Key, the payment transaction process comprising the steps of:
responsive to receiving a request for an application cryptogram at the user device, generating the application cryptogram on the basis of a the session key received from the issuing bank; and
transmitting the generated application cryptogram from the user device to a point of-sale terminal for verification thereof by the issuing bank and authorization of the payment transaction.

4. The computer readable medium of claim 3 , wherein the user device comprises a first processing portion comprising a first application environment within a secure element and a second processing portion comprising a second application environment external to the secure element, and the computer program is executed within the second application environment.

5. A user device comprising:
a processor; and
a non-transitory computer readable medium comprising code, executable by the processor, for implementing operations including:
receiving, by the user device via a communication network, a first session key different from a Master Key from a remote entity, the first session key based on the Master Key stored at the remote entity, the user device comprising a first processing portion and a second processing portion, the first processing portion comprising a first application environment and the second processing portion comprising at least a second application environment, the second processing portion storing a payment application, and the payment application not storing the Master Key on the user device, wherein the first session key is usable for a limited number of one or more transactions;
in response to receiving the first session key, storing, by the second processing portion, the first session key;
in response to storing the first session key, provisioning, by the second processing portion, the payment application with the first session key;
receiving, by the user device via the communication network, a second session key from the remote entity, the second session key based on the Master Key stored at the remote entity, the second session key being different from the first session key and the Master Key;
storing, by the second processing portion, the second session key;
receiving, at the payment application, a request for an application cryptogram, wherein the request is from a point-of-sale terminal; and
in response to the receiving, performing, by the payment application, an authorization process, wherein authorization process comprises:
generating, by the payment application, the application cryptogram based on the received first session key; and
transmitting, by the payment application, the generated application cryptogram to the point-of-sale terminal.

6. The user device of claim 5 , wherein the operations further comprise:
discarding, by the user device, the first session key after generating the application cryptogram.

7. The user device of claim 5 , wherein the operations further comprise:
provisioning, by the second processing portion, the second session key to the payment application in response to a predetermined criterion being satisfied.

8. The user device of claim 7 , wherein the predetermined criterion comprises a day, month and year maintained by a certificate provisioning entity matching a date corresponding to a predetermined amount of time having elapsed since the provisioning of the first session key to the user device.

9. The user device of claim 7 , wherein the predetermined criterion comprises a number of session keys stored by the user device falling below a predetermined value.

10. The user device of claim 5 , wherein the user device is a mobile communications device.

11. The user device of claim 5 , wherein the second application environment is a Trusted Execution Environment, and the operations further comprise one or more of:
storing, by the user device, the first session key in the Trusted Execution Environment;
storing, by the user device, at least part of the payment application in the Trusted Execution Environment; or
executing, by the user device, at least part of the payment application in the Trusted Execution Environment.

12. The user device of claim 5 , wherein the transmitting of the generated application cryptogram comprises using a radio frequency communications protocol.

13. The user device of claim 5 , wherein the first session key is valid only for a payment transaction.

14. The user device of claim 5 , therein the operations further comprise:
storing, by the user device, a plurality of session keys including the first session key, the second session key, and a third session key sent from the remote entity.

15. The user device of claim 14 , wherein the plurality of session keys are stored encrypted in the user device.

16. The user device of claim 15 , wherein only one of the plurality of session keys are decrypted at a time.

17. The user device of claim 16 , wherein the operations further comprise:
receiving, by the user device, user input; and
decrypting, by the user device, one of the plurality of session keys using the user input as a decryption key.

18. The user device of claim 5 , wherein the operations further comprise:
periodically receiving, by the user device, new session keys from the remote entity.

19. The user device of claim 5 , wherein a payment transaction conducted using the first session key is denied in response to an amount of time between provisioning of the first session key and th

Assignees

• Visa Europe Ltd

Inventors

• Fiske Stuart

Classifications

• H04L2209/56

  Financial cryptography, e.g. electronic payment or e-cash · CPC title

• G06Q20/322

  Aspects of commerce using mobile devices [M-devices] · CPC title

• H04L9/3263

  involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements (network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823) · CPC title

• G06Q20/3829 Primary

  involving key management · CPC title

• G07F7/127

  in which both online and offline card verification can take place · CPC title