Proximity interaction system including secure encryption scheme

1. A method comprising:

receiving, at a computing device from an access device in a transaction, initial data including a unique identifier associated with the access device, the initial data being transmitted by the access device to the computing device using signals generated by the access device;

transmitting, by the computing device to a server computer, first data comprising the unique identifier, wherein the server computer thereafter generates encrypted data using a session key;

in response to transmitting the first data, receiving, by the computing device from the server computer, second data comprising the encrypted data;

transmitting, by the computing device to the access device, at least a portion of the second data to the access device using signals generated by the computing device, wherein the access device transmits to the server computer third data comprising the encrypted data, which decrypts the encrypted data using the session key then uses the decrypted data to obtain authorization for the transaction; and

receiving, by the computing device, an indication that the transaction was approved or denied, and

wherein the access device generates the signals including the initial data using a first speaker of the access device, and wherein the computing device generates the signals with the at least the portion of the second data using a second speaker of the computing device.

2. The method of claim 1 , wherein the signals including the initial data and the signals including the at least the portion of the second data are ultrasonic sound signals.

3. The method of claim 1 , wherein the unique identifier comprises a beacon ID.

4. The method of claim 1 , wherein the first data comprises device information of the computing device.

5. The method of claim 1 , wherein the first data comprises user verification data.

6. The method of claim 1 , wherein the server computer compares the received unique identifier to another unique identifier provided to the access device to determine if they match.

7. The method of claim 1 , wherein the second data comprises a token.

8. The method of claim 1 , wherein the signals are sound signals.

9. The method of claim 1 , wherein the signals are high frequency sound signals.

10. The method of claim 1 , wherein the computing device is a mobile phone.

11. The method of claim 1 , wherein the second data comprises a cryptogram.

12. A system comprising:

one or more processors; and

one or more non-transitory computer readable media coupled to the one or more processors, the one or more non-transitory computer readable media comprising code, executable by the one or more processors, to implement a method comprising

receiving, from an access device, initial data including a unique identifier associated with the access device for a transaction, the initial data being transmitted by the access device to a computing device using signals generated by the access device,

transmitting, to a server computer, first data comprising the unique identifier, wherein the server computer thereafter generates encrypted data using a session key,

in response to transmitting the first data, receiving, from the server computer, second data comprising the encrypted data,

transmitting, to the access device, at least a portion of the second data to the access device using signals generated by the computing device, wherein the access device transmits to the server computer third data comprising the encrypted data, which decrypts the encrypted data using the session key then uses the decrypted data to obtain authorization for the transaction, and

receiving an indication that the transaction was approved or denied, and

wherein the access device generates the signals including the initial data using a first speaker of the access device, and wherein the computing device generates the signals with the at least the portion of the second data using a second speaker of the computing device.

13. The system of claim 12 , wherein the unique identifier associated with the access device is associated with an expiration date and/or an expiration time, and is invalid after the expiration date and/or expiration time.

14. The system of claim 12 , wherein the computing device is a mobile phone.

15. The system of claim 12 , wherein the computing device further comprises an application, an ultrasound SDK and a microphone.

16. The system of claim 12 , wherein in the method, the unique identifier is received from the access device via ultrasound.

17. The system of claim 12 , wherein the computing device includes a user interface that allows a user to enter item information.

18. A server computer, comprising:

a processor; and

a non-transitory computer readable medium coupled to the processor, the computer readable medium comprising code, executable by the processor, to implement a method comprising,

receiving, from a computing device, first data comprising at least a unique identifier associated with an access device, the first data being associated with a transaction being conducted between the computing device and the access device,

verifying the first data utilizing the received unique identifier,

in response to verifying the first data, transmitting second data to the computing device, wherein receipt of the second data by the computing device causes the computing device to transmit the second data to the access device, wherein the second data is in the form of sound data,

receiving, from the access device, third data,

verifying the third data at the server computer, and

when the third data is verified, transmitting, by the server computer, an authorization request message for the transaction.