Generating transaction identifiers

1. A portable electronic device, comprising:

an antenna;

an interface circuit, coupled to the antenna, configured to wirelessly communicate with an other electronic device; and

a secure element, coupled to the interface circuit, configured to:

in response to an authentication-complete flag being set by the secure element, conduct, through the interface circuit, a financial transaction with the other electronic device;

determine, after financial-account information is communicated to the other electronic device, a first unique transaction identifier for the financial transaction based on the financial-account information;

receive, from an other entity associated with the financial transaction, financial transaction receipt information associated with the financial transaction, wherein the financial transaction receipt information includes a second unique transaction identifier independently computed by the other entity based on the financial-account information communicated to the other electronic device,

wherein the other entity comprises a payment network that processes payment for the financial transaction using a financial account specified by the financial-account information;

compare the first unique transaction identifier with the second unique transaction identifier; and

associate the received financial transaction receipt information with the financial transaction in response to the second unique transaction identifier matching the first unique transaction identifier.

2. The portable electronic device of claim 1 , wherein the first unique transaction identifier corresponds to a secure hash of the financial-account information.

3. The portable electronic device of claim 1 , wherein the financial-account information is associated with a credit card.

4. The portable electronic device of claim 1 , further comprising

a processor, communicatively coupled to the interface circuit, wherein the processor is configured to receive the first unique transaction identifier from the secure element and to append a timestamp to the first unique transaction identifier, and wherein the timestamp corresponds to when the financial-account information was communicated to the other electronic device.

5. The portable electronic device of claim 1 , wherein:

the secure element comprises a payment applet associated with the financial-account information, and

during the financial transaction, the payment applet is configured to execute in an environment of the secure element, and is configured to conduct the financial transaction and to determine the first unique transaction identifier.

6. The portable electronic device of claim 1 , wherein the other entity further comprises a financial institution associated with the financial account.

7. The portable electronic device of claim 1 , wherein the financial-account information includes: a token associated with a financial-account identifier, an expiration date of a financial account associated with the financial-account information, and a numerical value corresponding to a number of financial transactions conducted by the portable electronic device.

8. The portable electronic device of claim 7 , wherein:

the secure element is further configured to dynamically generate a dynamic card verification value for the financial transaction, and

the financial-account information includes the dynamic card verification value.

9. The portable electronic device of claim 1 , wherein the interface circuit is further configured to receive, from a payment network that processes payment for the financial transaction and includes the other entity, a notification associated with the financial transaction, and wherein the secure element is further configured to:

request, from the payment network, the financial transaction receipt information associated with the financial transaction based on the notification.

10. The portable electronic device of claim 9 , wherein the financial transaction receipt information includes one or more of: a status of the financial transaction, an identifier for a counterparty in the financial transaction, or a financial amount of the financial transaction.

11. The portable electronic device of claim 1 , wherein the financial transaction receipt information comprises a first set of information and a second set of information, and the secure element is further configured to:

receive, from a second entity associated with the financial transaction, the second set of information.

12. The portable electronic device of claim 1 , wherein the financial-account information comprises an account number associated with the portable electronic device and a combination of a counter value and a dynamic card verification value.

13. The portable electronic device of claim 1 , wherein the secure element is further configured to:

determine whether the authentication-complete flag is supported;

in response to a determination that the authentication-complete flag is supported, determine whether the authentication-complete flag is set; and

in response to a determination that the authentication-complete flag is not supported or the determination that the authentication-complete flag is set, conduct the financial transaction with the other electronic device.

14. The portable electronic device of claim 1 , wherein the secure element is further configured to update and store a status of the financial transaction in a memory to associate the received financial transaction receipt information with the financial transaction when the second unique transaction identifier matches the first unique transaction identifier.

15. The portable electronic device of claim 1 , wherein the second unique transaction identifier is independently computed by the other entity without the portable electronic device communicating the first unique transaction identifier to the other entity.

16. A portable electronic device, comprising:

an antenna; and

an interface circuit, coupled to the antenna, configured to communicate with an other electronic device via near-field communication;

a secure element, coupled to the interface circuit, which includes a payment applet associated with financial-account information, wherein, during a financial transaction, the payment applet is configured to execute in an environment of the secure element and is configured to:

in response to an authentication-complete flag being set by the secure element, conduct the financial transaction with the other electronic device;

after the financial-account information is communicated to the other electronic device during the financial transaction, determine a first unique transaction identifier for the financial transaction based on the financial-account information, wherein the financial-account information is associated with a credit card;

receive, from an other entity associated with the financial transaction, financial transaction receipt information associated with the financial transaction, wherein the financial transaction receipt information includes a second unique transaction identifier independently computed by the other entity based on the financial-account information communicated to the other electronic device,

wherein the other entity comprises a payment network that processes payment for the financial transaction using a financial account specified by the financial-account information;

compare the first unique transaction identifier with the second unique transaction identifier; and

associate the received financial transaction receipt information with the financial transaction in response to the second unique transaction identifier matching the first unique transaction identifier.

17. The portable electronic device of claim 16 , wherein the first unique transaction identifier corresponds to a secure hash of the financial-account information.

18. The portable electronic device of claim 16 , wherein the interface circuit is further configured to receive, from a payment network that processes payment for the financial transaction and includes the other entity, a notification associated with the financial transaction, and wherein the secure element is further configured to:

request, from the payment network, the financial transaction receipt information associated with the financial transaction based on the notification.

19. The portable electronic device of claim 16 , wherein the secure element is further configured to update and store a status of the financial transaction in a memory to associate the received financial transaction receipt information with the financial transaction when the second unique transaction identifier matches the first unique transaction identifier.

20. A portable electronic device, comprising:

an interface circuit configured to wirelessly communicate with an other electronic device; and

a secure element, coupled to the interface circuit, configured to:

in response to an authentication-complete flag being set by the secure element, conduct, through the interface circuit, a financial transaction with the other electronic device;

determine, after financial-account information is communicated to the other electronic device, a first unique transaction identifier for the financial transaction based on the financial-account information;

receive, from an other entity associated with the financial transaction, financial transaction receipt information associated with the financial transaction, wherein the financial transaction receipt information includes a second unique transaction identifier independently computed by the other entity based on the financial-account information communicated to the other electronic device,

wherein the other entity comprises a payment network that processes payment for the financial transaction using a financial account specified by the financial-account information;

compare the first unique transaction identifier with the second unique transaction identifier; and

update and store a status of the financial transaction in a memory to associate the received financial transaction receipt information with the financial transaction in response to the second unique transaction identifier matching the first unique transaction identifier; and

display the received financial transaction receipt information on a display of the portable electronic device.

21. The portable electronic device of claim 20 , wherein the other entity further comprises a financial institution associated with the financial account.

22. The portable electronic device of claim 20 , wherein:

the secure element includes a payment applet associated with the financial-account information, and

during the financial transaction, the payment applet is configured to execute in an environment of the secure element, and is configured to conduct the financial transaction and to determine the first unique transaction identifier.

23. The portable electronic device of claim 20 , wherein:

the secure element is further configured to dynamically generate a dynamic card verification value for the financial transaction, and

the financial-account information includes the dynamic card verification value.