Systems and methods for contactless payment authorization

A system for contactless payment authorization, the system comprising:

• an identifier;
• and
• a mobile communication device that communicates with a payment terminal over a near-field communication channel,
• wherein the mobile communication device is equipped with a transmitting and receiving element for contactless communication with the identifier, and
• wherein the identifier is supplied with electrical energy from an electromagnetic field of the mobile communication device and comprises a processor for electronically signing a received alphanumeric string, a transmitting and receiving element for communication with the mobile communication device, a block for transforming the electromagnetic field into the electrical energy, and a memory.

An identifier for use in a contactless payment authorization system, the identifier for use with a mobile communications device in contactless communication with a payment terminal, the identifier comprising:

• a processor for electronically signing an identifying code received from the mobile communications device;
• a transmitting and receiving unit for communicating with the mobile communication device, the transmitting and receiving unit for receiving the identifying code and transmitting the electronically signed identifying code;
• a memory that contains a stored identification number and a key for use in electronically signing the received identifying code;
• and
• a block for transforming an electromagnetic field of the mobile communication device into electrical energy that is supplied to the processor, the transmitting and receiving unit, and to the memory.