Relay attack prevention using RSSIPPLX
First Claim
1. A passive keyless entry receiver system, comprising:
- a receiver configured to receive a wireless signal having a data packet with a payload comprising a plurality of different power levels having a plurality of peak RSSI (Receive Signal Strength Indicator) levels corresponding to the plurality of different power levels;
a plurality of RSSI peak payload registers, respectively configured to store one of the plurality of peak RSSI levels for a RSSI step of the payload;
a RSSI difference register configured to store one or more RSSI differences between the plurality of peak RSSI levels;
a comparison element configured to compare the one or more RSSI differences to one or more expected RSSI differences to determine if the plurality of different power levels correspond to an expected sequence of power level differences;
one or more RSSI start registers configured to store starting positions of one or more RSSI steps within the payload; and
one or more RSSI stop registers configured to store stopping positions of the one or more RSSI steps within the payload, wherein the starting positions and the stopping positions define a plurality of distinct ranges within the data packet that correspond to the one or more RSSI steps over which peak values are measured.
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Accused Products
Abstract
The disclosed invention relates to a passive keyless entry receiver system having an application controller that is activated upon receipt of an entire payload of a data packet to determine if peak RSSI levels for a plurality of RSSI steps within the payload match an expected sequence of peak RSSI levels (i.e., if a fingerprint is genuine). The receiver system has a receiver that receives a wireless signal having a data packet with a plurality of power levels within a plurality of RSSI steps of the payload. The receiver system writes a plurality of peak RSSI levels to a plurality of RSSI peak payload registers that store the peak RSSI levels for RSSI steps of the payload. Once an entire payload of a data packet has been received an application controller determines if the peak payloads correspond to an expected sequence of power levels.
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Citations
17 Claims
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1. A passive keyless entry receiver system, comprising:
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a receiver configured to receive a wireless signal having a data packet with a payload comprising a plurality of different power levels having a plurality of peak RSSI (Receive Signal Strength Indicator) levels corresponding to the plurality of different power levels; a plurality of RSSI peak payload registers, respectively configured to store one of the plurality of peak RSSI levels for a RSSI step of the payload; a RSSI difference register configured to store one or more RSSI differences between the plurality of peak RSSI levels; a comparison element configured to compare the one or more RSSI differences to one or more expected RSSI differences to determine if the plurality of different power levels correspond to an expected sequence of power level differences; one or more RSSI start registers configured to store starting positions of one or more RSSI steps within the payload; and one or more RSSI stop registers configured to store stopping positions of the one or more RSSI steps within the payload, wherein the starting positions and the stopping positions define a plurality of distinct ranges within the data packet that correspond to the one or more RSSI steps over which peak values are measured. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A passive keyless entry receiver system, comprising:
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a receiver configured to receive a wireless signal having a data packet with a payload comprising a plurality of different power levels and to generate an RSSI (Receive Signal Strength Indicator) signal corresponding to a plurality of peak RSSI levels of the plurality of different power levels; a plurality of RSSI peak payload registers, respectively configured to store one of the plurality of peak RSSI levels for a RSSI step of the payload having a pre-defined bit range; one or more RSSI start registers configured to store starting positions of one or more RSSI steps within the payload of the data packet; one or more RSSI stop registers configured to store stopping positions of the one or more RSSI steps within the payload of the data packet, wherein the starting positions and the stopping positions define a plurality of distinct ranges within the data packet that correspond to RSSI steps over which the plurality of peak RSSI levels are measured; an application controller, which upon receipt of an entirety of the payload is configured to utilize a plurality of peak RSSI levels stored in the plurality of RSSI peak payload registers to determine if the plurality of peak RSSI levels correspond to an expected sequence of power levels; a RSSI expected value register configured to store one or more expected RSSI differences between the plurality of peak RSSI levels; and a comparison element configured to compare the one or more expected RSSI differences to one or more RSSI differences and to set the value of a result bit based upon the comparison. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A method of preventing a relay attack, comprising:
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receiving a wireless signal having a data packet with a payload comprising a plurality of different power levels; determining a plurality of peak RSSI (Receive Signal Strength Indicator) levels within a plurality of pre-defined bit ranges within the payload, wherein the plurality of peak RSSI levels correspond to the plurality of different power levels and wherein the pre-defined bit ranges are defined by separate starting positions within the payload and stopping positions within the payload; storing the plurality of peak RSSI levels in RSSI peak payload registers until an entire payload of the data packet is received; calculating one or more RSSI differences between peak RSSI levels for one of the plurality of pre-defined bit ranges; and comparing the one or more RSSI differences to expected RSSI differences to determine if the plurality of different power levels of the payload correspond to an expected sequence of power levels. - View Dependent Claims (14, 15, 16, 17)
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Specification