Mobile payment using picture messaging

A point-of-sale terminal comprising:

• a processor;
• and
• a memory that stores instructions that, when executed by the processor, cause the processor to perform operations comprising
• receiving output of a scanner that is in communication with the point-of-sale terminal, the output comprising results of the scanner scanning an image displayed on a display of a mobile device, the image comprising a payment key and being generated at a server in response to a key request submitted by the mobile device, and the key request comprising a user-input store identifier,
• extracting the payment key from the image,
• generating a bill, the bill comprising the payment key, a terminal-input store identifier, and an amount to be charged, and
• transmitting the bill to the server so that the server can determine whether the terminal-input store identifier is the same as the user-input store identifier and, in response to determining that the terminal-input store identifier is the same as the user-input store identifier, cause a user account associated with the mobile device to be charged the amount to be charged.

A mobile device comprising:

• a display;
• a processor;
• and
• a memory that stores instructions that, when executed by the processor, cause the processor to perform operations comprising
• receiving input of a user-input store identifier identifying a store associated with a point-of-sale terminal,
• generating a key request, the key request comprising the user-input store identifier,
• transmitting the key request to a server,
• receiving an image from the server, the image comprising a payment key,
• presenting the image on the display so that a scanner associated with the point-of-sale terminal can scan the image to extract the payment key from the image, generate a bill comprising the payment key, a terminal-input store identifier, and an amount to be charged, and send the bill to the server so that the server can determine whether the terminal-input store identifier is the same as the user-input store identifier, and
• receiving an indication that a user account associated with the mobile device has been charged the amount to be charged in response to the server determining that the terminal-input store identifier is the same as the user-input store identifier.