Backscatter limited tags
First Claim
1. A method of communicating with a population of radio frequency identification (RFID) tags, comprising:
- transmitting a first interrogation signal;
receiving a first response to the first interrogation signal from at least one RFID tag at a first received signal strength, wherein the response includes at least a portion of a first identification code;
determining a secure power level as a lowest power level such that a second response to a second interrogation signal is received;
transmitting the second interrogation signal that includes a request for confidential information, a command to transmit a response to the second interrogation signal at the determined secure power level, and said first identification code, wherein said at least one RFID tag is configured to adjust power to transmit the response to the second interrogation signal at the determined secure power level based on the requestreceiving the second response to the second interrogation signal at a second received signal strength, wherein the second response includes confidential information, wherein the second received signal strength is less than the first received signal strength;
wherein if the second response to the second interrogation is not received, transmitting a third interrogation signal that includes a command to re-transmit the confidential information at an increased power level, and receiving a third response to the third interrogation signal at a third received signal strength, wherein the third response includes confidential information, wherein the third received signal strength is less than the first received signal strength and is higher than the second received signal strength.
4 Assignments
0 Petitions
Accused Products
Abstract
Methods and apparatuses for secure communications of confidential information are provided. In an embodiment, a method of communicating with a population of radio frequency identification tags includes transmitting a first interrogation signal, receiving a response to the first interrogation signal from at least one RFID tag at a first received signal strength including at least a portion of a first identification code, and transmitting a second interrogation signal that includes a request for confidential information, a command to transmit a response to the second interrogation signal at a secure power level, and the first identification code. In another embodiment, a method for communicating with an RFID tag includes receiving an interrogation signal that includes a request for confidential information and transmitting a response to the interrogation signal at a secure power level. The response includes the confidential information.
29 Citations
14 Claims
-
1. A method of communicating with a population of radio frequency identification (RFID) tags, comprising:
-
transmitting a first interrogation signal; receiving a first response to the first interrogation signal from at least one RFID tag at a first received signal strength, wherein the response includes at least a portion of a first identification code; determining a secure power level as a lowest power level such that a second response to a second interrogation signal is received; transmitting the second interrogation signal that includes a request for confidential information, a command to transmit a response to the second interrogation signal at the determined secure power level, and said first identification code, wherein said at least one RFID tag is configured to adjust power to transmit the response to the second interrogation signal at the determined secure power level based on the request receiving the second response to the second interrogation signal at a second received signal strength, wherein the second response includes confidential information, wherein the second received signal strength is less than the first received signal strength; wherein if the second response to the second interrogation is not received, transmitting a third interrogation signal that includes a command to re-transmit the confidential information at an increased power level, and receiving a third response to the third interrogation signal at a third received signal strength, wherein the third response includes confidential information, wherein the third received signal strength is less than the first received signal strength and is higher than the second received signal strength. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 14)
-
-
10. A system for performing a radio frequency identification (RFID) communications, comprising:
-
reader means for transmitting an interrogation signal and determining a secure power level for confidential information, wherein the determined secure power level comprises one of a plurality of power levels; tag means for receiving the interrogation signal that includes a request for the confidential information and the determined secure power level; tag means for transmitting a response to the interrogation signal at the determined secure power level including the confidential information, and for transmitting a response to an interrogation signal for regular information at a regular power level, wherein the determined secure power level is less than the regular power level; reader means for receiving the response, wherein the determined secure power level is the lowest power level of the plurality of power levels for the tag means for transmitting such that the response from the tag means for transmitting is received by the reader means for receiving; and reader means for adjusting the secure power level responsive to a failure in receiving the response. - View Dependent Claims (11, 12, 13)
-
Specification