Secure two-way RFID communications
First Claim
1. In an RFID system, a method of communicating securely between a reader and a tag, comprising:
- at the reader, modulating an RF carrier signal with a noise encryption signal to produce a noise-encrypted RF carrier signal;
transmitting the noise-encrypted RF carrier signal to the tag; and
at the tag, backscatter modulating the noise-encrypted RF carrier signal with a tag information signal to produce a noise-encrypted backscattered signal.
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Accused Products
Abstract
Methods and apparatus for providing secure two-way (reader-to-tag and tag-to-reader) RFID communications. According to one aspect of the invention, a tag receives a noise-encrypted RF carrier signal from a reader and backscatter modulates it with tag information. Eavesdroppers cannot extract the tag information from the backscattered signal because it is masked by the noise encryption. According to another aspect of the invention, establishing a secure two-way RFID communication link includes a reader modulating a carrier signal with a noise encryption signal and broadcasting the noise-encrypted carrier to a singulated tag. The tag backscatter modulates the noise-encrypted carrier with a first portion of a key and/or a one-time pad pseudorandom number. If a key is used, upon receiving the backscattered signal the reader verifies that the tag is authentic, and, if verified as authentic, transmits a second portion of the key, possibly encrypted by a function depending on the one-time pad pseudorandom number, to the tag.
144 Citations
80 Claims
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1. In an RFID system, a method of communicating securely between a reader and a tag, comprising:
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at the reader, modulating an RF carrier signal with a noise encryption signal to produce a noise-encrypted RF carrier signal;
transmitting the noise-encrypted RF carrier signal to the tag; and
at the tag, backscatter modulating the noise-encrypted RF carrier signal with a tag information signal to produce a noise-encrypted backscattered signal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An RFID system, comprising:
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a reader operable to modulate an RF carrier signal with a noise encryption waveform and broadcast the resulting noise-encrypted RF carrier signal to a population of tags; and
at least one of the tags of the population of tags configured to receive the noise-encrypted RF carrier signal and backscatter modulate the received noise-encrypted RF carrier signal with a tag information signal. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. A method of preventing an eavesdropper from intercepting a backscattered signal from a tag in an RFID system, comprising:
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applying amplitude modulation to a carrier signal generated by a reader;
broadcasting the modulated carrier signal to a tag of the RFID system;
backscatter modulating the modulated carrier signal with tag information. - View Dependent Claims (17)
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18. A method of preventing an eavesdropper from intercepting a backscattered signal from a tag in an RFID system, comprising:
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applying phase or frequency modulation to a carrier signal generated by a reader;
broadcasting the modulated carrier signal to a tag of the RFID system; and
backscatter modulating the modulated carrier signal with tag information. - View Dependent Claims (19, 20, 21)
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22. A method of forming an RFID system, comprising:
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providing a reader designed to modulate a carrier signal with a noise encryption signal to produce a noise-encrypted carrier signal; and
providing one or more tags designed to receive a broadcast of the noise-encrypted carrier signal and backscatter modulate a reverse link encrypted signal modulated by tag information. - View Dependent Claims (23, 24, 25, 26)
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27. An RFID system, comprising:
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a reader having;
a voltage controlled oscillator (VCO) operable to produce a carrier signal;
a variable gain amplifier (VGA) having a first input configured to receive the carrier signal from the VCO and a second gain control input configured to receive an amplitude modulation signal, said VGA operable to generate an amplitude modulated carrier signal; and
one or more tags configured to receive and backscatter modulate the amplitude modulated carrier signal with tag information stored on the one or more tags, wherein said amplitude modulation signal operates to noise encrypt the backscatter modulated signal. - View Dependent Claims (28)
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29. An RFID system, comprising:
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a reader having a voltage controlled oscillator (VCO) configured to receive a phase or frequency modulation signal and provide a phase or frequency modulated carrier signal; and
one or more tags configured to receive and backscatter modulate the phase or frequency modulated carrier signal with tag information stored on the one or more tags, wherein said phase or frequency modulation signal operates to noise encrypt the backscatter modulated signal. - View Dependent Claims (30)
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31. A method of establishing a secure two-way communication link between a reader and a tag in an RFID system, comprising:
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singulating a tag from a population of tags;
at the reader, modulating a carrier signal with a noise encryption signal;
at the singulated tag, backscatter modulating the noise-encrypted signal with a first portion of a key;
at the reader, verifying that the singulated tag is an authentic tag; and
at the reader, transmitting a second portion of said key to the singulated tag. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39)
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40. A method of establishing a secure two-way communication link between a reader and a tag in an RFID system, comprising:
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singulating a tag from a population of tags;
at the reader, modulating a carrier signal with a noise encryption signal; and
at the singulated tag, backscatter modulating the noise-encrypted signal with a one-time pad. - View Dependent Claims (41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 60, 65)
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54. A method of establishing a secure two-way communication link between a reader and a tag in an RFID system, comprising:
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singulating a tag from a population of tags;
at the reader, modulating a carrier signal with a noise encryption signal;
at the singulated tag, backscatter modulating the noise encrypted signal with a first portion of a key and a one-time pad;
at the reader, verifying that the singulated tag is an authentic tag; and
at the reader, transmitting a second portion of said key to the singulated tag. - View Dependent Claims (55, 56, 57, 58, 59, 61, 62, 63, 64, 66, 67, 68, 69, 70, 71)
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72. A reader for an RFID system, comprising:
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a noise encryption signal generator; and
a modulator operable to noise encrypt a carrier signal, wherein said reader is operable to transmit a noise-encrypted RF carrier signal to one or more tags and receive a noise-encrypted backscatter signal modulated by tag information, when the reader is configured in the RFID system. - View Dependent Claims (73, 74, 75, 76)
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77. A reader for an RFID system, comprising:
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means for noise encrypting an RF carrier signal broadcast to a tag;
means for receiving a noise-encrypted backscatter modulated signal from the tag;
means for removing the noise encryption from the received noise-encrypted backscatter modulated signal; and
means for recovering tag information sent in the noise-encrypted backscatter modulated signal. - View Dependent Claims (78, 79, 80)
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Specification