Mutual authentication security system with recovery from partial programming
First Claim
1. A method of programming memory contents in an electronic key using a base station, said method comprising the steps of:
- transferring a pre-existing secret code value to said electronic key, said pre-existing code value having a predetermined number of data segments;
said electronic key comparing a received secret code value with a stored secret code value in a memory location within said electronic key;
if said comparison detects a non-match, then suspending interaction with said base station;
if said comparison detects a match, then continuing interaction with said base station to accept a new secret code value transmitted from said base station to said electronic key according to said data segments; and
said base station verifying acceptance of said new secret code value and if said new secret code value is not verified then reprogramming said electronic key using the steps comprising;
forming a first recovery code comprising a leading portion having values matching a corresponding portion of said pre-existing secret code and a trailing portion having values matching a corresponding portion of said new secret code;
transmitting said first recovery code to said electronic key for comparison with said stored secret code value;
said electronic key comparing a received secret code value in response to said first recovery code with said stored secret code value;
if said comparison detects a non-match, then suspending interaction with said base station; and
if said comparison detects a match, then continuing interaction with said base station to accept said new secret code value after re-transmission from said base station to said electronic key according to said data segments.
9 Assignments
0 Petitions
Accused Products
Abstract
Memory contents in an electronic key are re-programmed using a base station from a multi-byte pre-existing or default value. If writing the new secret code value is interrupted and results in a partially-written value then a first recovery code is formed comprising a leading portion having values matching a corresponding portion of the pre-existing secret code and a trailing portion having values matching a corresponding portion of the new secret code. The first recovery code is transmitted to the electronic key for comparison with the stored secret code value. The electronic key compares a received secret code value in response to the first recovery code with the stored secret code value. If the comparison detects a non-match, then interaction with the base station is suspended. If the comparison detects a match, then interaction with the base station is continued in order to accept the new secret code value after re-transmission in full from the base station.
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Citations
8 Claims
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1. A method of programming memory contents in an electronic key using a base station, said method comprising the steps of:
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transferring a pre-existing secret code value to said electronic key, said pre-existing code value having a predetermined number of data segments;
said electronic key comparing a received secret code value with a stored secret code value in a memory location within said electronic key;
if said comparison detects a non-match, then suspending interaction with said base station;
if said comparison detects a match, then continuing interaction with said base station to accept a new secret code value transmitted from said base station to said electronic key according to said data segments; and
said base station verifying acceptance of said new secret code value and if said new secret code value is not verified then reprogramming said electronic key using the steps comprising;
forming a first recovery code comprising a leading portion having values matching a corresponding portion of said pre-existing secret code and a trailing portion having values matching a corresponding portion of said new secret code;
transmitting said first recovery code to said electronic key for comparison with said stored secret code value;
said electronic key comparing a received secret code value in response to said first recovery code with said stored secret code value;
if said comparison detects a non-match, then suspending interaction with said base station; and
if said comparison detects a match, then continuing interaction with said base station to accept said new secret code value after re-transmission from said base station to said electronic key according to said data segments. - View Dependent Claims (2, 3)
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4. A base station for programming a new secret code value in a memory of an electronic key for a vehicle, said electronic key having a default secret code value prior to programming said memory contents, said default secret code value and said new secret code value each having a predetermined number of data segments, said base station comprising:
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a transceiver for wirelessly communicating with said electronic key; and
a controller storing said default secret code value and said new secret code value, said controller programmed to perform the steps of;
transferring said default secret code value from said base station to said electronic key;
transferring said new secret code value from said base station to said electronic key according to said data segments; and
verifying acceptance of said new secret code value and if said new secret code value is not verified then reprogramming said electronic key using the steps comprising;
forming a first recovery code comprising a leading, portion having values matching a corresponding portion of said default secret code and a trailing portion having values matching a corresponding portion of said new secret code;
transmitting said first recovery code to said electronic key for comparison with said stored secret code value;
re-transferring said new secret code value from said base station to said electronic key. - View Dependent Claims (5, 6, 7, 8)
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Specification