Encrypted payment image

1. A machine-readable non-transitory storage medium of a mobile computing device comprising instructions executable by a processor to:

capture, using a camera of the mobile computing device, an invoice image of a barcode displayed by a retailer and that encodes information regarding a purchase transaction initiated by a user of the mobile computing device with the retailer;

decode the information regarding the purchase transaction from the barcode of the invoice image and display the information to the user;

in response to receiving confirmation from the user of the information:

generate a binary version of the invoice image;

encrypt the binary version of the invoice image with an encryption key comprising payment account information that identifies a payment account of the user with which the user is paying for the purchase transaction, the encryption key known by a payment processor and unknown by the retailer; and

display the encrypted version of the invoice image to the retailer, the retailer capturing the encrypted version to transmit to the payment processor to fulfill payment for the purchase transaction against the payment account,

wherein the payment for the purchase transaction is fulfilled without the retailer learning the payment account information.

2. The machine-readable non-transitory storage medium of claim 1 , wherein instructions to encrypt the binary version of the invoice image comprise instructions executable by the processor to encrypt the payment information using at least one of: hash-based message authentication code encryption or public key infrastructure encryption.

3. The machine-readable non-transitory storage medium of claim 1 , wherein instructions to generate the binary version of the invoice image comprise instructions executable by the processor to generate a binary version of an invoice barcode image.

4. The machine-readable non-transitory storage medium of claim 1 , further comprising instructions executable by the processor to transmit the displayed image to a payment entity.

5. The machine-readable non-transitory storage medium of claim 1 , wherein the payment account information comprises a payment account number.

6. The machine-readable non-transitory storage medium of claim 1 , wherein the payment account information comprises a credit card number.

7. The machine-readable non-transitory storage medium of claim 1 , further comprising instructions executable by the processor to:

store payment information on machine-readable non-transitory storage medium, wherein the payment information comprises information identifying different payment accounts; and

display a user interface that allows a user to select one of the different payment accounts as the payment account identified by the payment account information.