Truncation, compression, and encryption of rfid tag communications

Abstract

Methods, systems, and apparatuses for RFID tags, RFID readers, communications algorithms, and RFID-related applications are described herein. In an aspect of the invention, an RFID tag is capable of storing data, receiving a signal from a reader, determining a response taking into account the tag mode and the data, and transmitting a response to the reader. The data includes a first plurality of bits and a second plurality of bits. The tag mode may be set by a current or a prior command by the reader. Depending on the tag mode, the response may be complete, or the second plurality of bits may be truncated, compressed, or encrypted. In an aspect of the invention, the response includes an implicit indication of whether the response is complete, truncated, encrypted, or compressed. In another aspect of the invention, a command from the reader indicates how many bits should be truncated, compressed, or encrypted.

1 . A radio frequency identification (RFID) system capable of distinguishing standard tag data and truncated tag data representing a serialized identifier, comprising:
 a processor receiving a tag reply, examining a bit length of the received reply, comparing a resulting word length to the bit length of the data structure implied by a received header of the tag reply, and determining that the serialized identifier has been truncated if the word length is less than what is indicated by the header of the tag.   
     
     
         2 . The RFID system of  claim 1 , wherein the processor further executes the step of:
 populating a data field indicating the serialized identifier has been truncated.   
     
     
         3 . The RFID system of  claim 1 , wherein the processor also recreates a GTIN-14 portion of the truncated identifier.