Methods and systems for the negotiation of a population of RFID tags with improved security

A radio frequency identification (RFID) tag, comprising:

• an antenna;
• a modulator coupled to said antenna, wherein said modulator is configured to backscatter modulate bits received from said antenna with response bits;
• a first storage that stores a first bit pattern that defines an identification number;
• and
• a second storage that stores a second bit pattern that does not include bits identifying an item with which the RFID tag is associated;
• wherein a first bit combination received from a reader causes said tag to respond to a communications operation with the first bit pattern;
• and
• wherein a second bit combination received from the reader causes said tag to respond to a communications operation with the second bit pattern.

A method for a radio frequency identification (RFID) tag to communicate with a RFID reader, wherein the tag stores a corresponding identification number, comprising:

• (a) receiving a first at least one bit from the reader to cause the tag to respond to a communications operation with a key;
• (b) engaging in a communications operation with the reader, including the steps of:
• (1) receiving a series of bits from the reader, and
• (2) responding to each bit of the series of bits with a randomly generated bit of the key.

A radio frequency identification (RFID) tag, comprising:

• an antenna;
• a modulator coupled to said antenna, wherein said modulator is configured to backscatter modulate bits received from said antenna with response bits;
• a storage that stores a bit pattern that defines an identification number;
• and
• a random bit pattern generator that generates said second bit pattern;
• wherein a first bit combination received from a reader causes said tag to respond to a communications operation with the first bit pattern;
• and
• wherein a second bit combination received from the reader causes said tag to respond to a communications operation with bits generated by said random bit pattern generator.

A method for a radio frequency identification (RFID) reader to communicate with a population of RFID tags, wherein each tag stores a corresponding identification number, wherein the identification number comprises a first bit pattern, comprising:

• (a) transmitting a first at least one bit to the population of tags to cause tags to respond to a communications operation with a second bit pattern;
• (b) performing a communications operation to singulate a first tag of the population of tags, including the step of:
• (1) transmitting a series of bits to the population of tags, and
• (2) receiving a corresponding bit of the second bit pattern from the first tag in response to each bit of the series of bits.

A method in a radio frequency identification (RFID) system that includes at least one RFID reader that communicates with a population of RFID tags, wherein each RFID tag stores a corresponding identification number, comprising:

• generating a key to identify an RFID tag of the population of RFID tags, wherein the key does not include bits identifying an item with which the RFID tag is associated;
• operating an interrogation protocol to at least identify the RFID tag in the population of RFIDs tags;
• and
• receiving bits of the generated key from the RFID tag during the interrogation protocol.

A method for a radio frequency identification (RFID) reader to communicate with a population of RFID tags, wherein each tag stores a corresponding identification number, wherein the identification number includes a first bit pattern, comprising:

• (a) transmitting a first at least one bit to the population of tags to cause tags to respond to a communications operation with a second bit pattern;
• (b) performing a communications operation to singulate a first tag of the population of tags;
• (c) transmitting a substantially constant signal to the population of tags;
• and
• (d) receiving a plurality of bits of the first bit pattern from the first tag during transmission of the substantially constant signal.

A method for a radio frequency identification (RFID) reader to communicate with a population of RFID tags, wherein each tag stores a corresponding identification number, wherein the identification number includes a first bit pattern, comprising:

• (a) transmitting a first at least one bit to the population of tags to cause tags to respond to an interrogation operation with the first bit pattern;
• (b) transmitting a substantially constant signal to the population of tags;
• and
• (c) receiving a plurality of bits of the first bit pattern from a first tag during transmission of the substantially constant signal.

A method for a radio frequency identification (RFID) tag to communicate with a RFID reader, wherein the tag stores a corresponding identification number, wherein the identification number comprises a first bit pattern, comprising:

• (a) randomly generating a second bit pattern;
• (b) receiving a symbol from the reader to cause the tag to respond with the second bit pattern;
• and
• (c) responding to the symbol with the second bit pattern.

A radio frequency identification (RFID) tag, comprising:

• an antenna;
• a modulator coupled to said antenna, wherein said modulator is configured to backscatter modulate bits received from said antenna with response bits;
• a first storage that stores a first bit pattern that defines an identification number;
• and
• a second storage that stores a second bit pattern that does not include bits identifying an item with which the RFID tag is associated;
• wherein a first symbol received from a reader causes said tag to respond with the first bit pattern;
• and
• wherein a second symbol received from the reader causes said tag to respond with the second bit pattern.