Security system having randomized synchronization code after power up
First Claim
1. A method, comprising the steps of:
- (a) powering up an integrated circuit, said integrated circuit being a part of a transmitting unit for a wireless security system;
(b) causing a sequential state machine of said integrated circuit to transition through a first number of states to generate a first binary number;
(c) using said first binary number to generate a first synchronization code and to output said first synchronization code onto an output terminal of said integrated circuit;
(d) after step (c), generating a second binary number by causing said sequential state machine of said integrated circuit to transition a predetermined number of times;
(e) using said second binary number to generate a verification code and to output said verification code onto said output terminal of said integrated circuit;
(f) after steps (a) through (e), powering down said integrated circuit;
(g) after step (f), powering up said integrated circuit;
(h) after step (g), causing said sequential state machine to transition through a second number of states to generate a third binary number; and
(i) using said third binary number to generate a second synchronization code and to output said second synchronization code onto said output terminal of said integrated circuit, said first and second synchronization codes being different digital values.
1 Assignment
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Accused Products
Abstract
A transmitting unit of a wireless security system having randomized successive ("rolling") verification codes transmits a different synchronization code each time that the transmitter unit is powered up. After power up, a pseudo-random value is generated by a pseudo-random number generator. The pseudo-random value is at least in part dependent upon a manipulation of a manually-operable switch of the transmitting unit. The pseudo-random value is incorporated into the first synchronization code transmitted after the first power up. If power to the transmitting unit is then interrupted and then resupplied, for example by removing and then replacing a battery, then the pseudo-random number generator generates another pseudo-random value, the value again depending at least in part upon a manipulation of the manually-operable switch. The pseudo-random value is then incorporated into the first synchronization code transmitted after the second power up. The first verification code used to gain access to the automobile is generated based on an initially fixed start value specific to the transmitting unit as well as on the initially randomized pseudo-random value.
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Citations
33 Claims
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1. A method, comprising the steps of:
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(a) powering up an integrated circuit, said integrated circuit being a part of a transmitting unit for a wireless security system; (b) causing a sequential state machine of said integrated circuit to transition through a first number of states to generate a first binary number; (c) using said first binary number to generate a first synchronization code and to output said first synchronization code onto an output terminal of said integrated circuit; (d) after step (c), generating a second binary number by causing said sequential state machine of said integrated circuit to transition a predetermined number of times; (e) using said second binary number to generate a verification code and to output said verification code onto said output terminal of said integrated circuit; (f) after steps (a) through (e), powering down said integrated circuit; (g) after step (f), powering up said integrated circuit; (h) after step (g), causing said sequential state machine to transition through a second number of states to generate a third binary number; and (i) using said third binary number to generate a second synchronization code and to output said second synchronization code onto said output terminal of said integrated circuit, said first and second synchronization codes being different digital values.
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2. A method, comprising the steps of:
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(a) powering up an integrated circuit; (b) causing a sequential state machine of said integrated circuit to transition through a first number of states to generate a first binary number; (c) using said first binary number to generate a first synchronization code and to output said first synchronization code onto an output terminal of said integrated circuit; (d) after step (c), generating a second binary number by causing said sequential state machine of said integrated circuit to transition a predetermined number of times; (e) using said second binary number to generate a verification code and to output said verification code onto said output terminal of said integrated circuit; (f) after steps (a) through (e), powering down said integrated circuit; (g) after step (f), powering up said integrated circuit; (h) after step (g), causing said sequential state machine to transition through a second number of states to generate a third binary number; and (i) using said third binary number to generate a second synchronization code and to output said second synchronization code onto said output terminal of said integrated circuit, wherein said sequential state machine comprises a first pseudo-random number generator and a second pseudo-random number generator, said method further comprising the steps of; (b1) after step (a) and before said first synchronization code is generated, loading said first pseudo-random number generator with a predetermined value; and (h1) after step (g) and before said second synchronization code is generated, loading said first pseudo-random number generator with said predetermined value; and wherein step (d) of generating a second binary number further comprises the steps of; causing said first pseudo-random number generator to transition to a new state; and causing said second pseudo-random number generator to transition to a new state. - View Dependent Claims (3)
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4. A method of operation of a wireless security system, said security system comprising a mobile transmitting unit and a receiving unit, comprising:
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step for generating first synchronization code information in said transmitting unit after power is first supplied to said transmitting unit; step for transmitting said first synchronization code information from said transmitting unit to said receiving unit; in said transmitting unit, step for using said first synchronization code information to generate verification code information in accordance with an encryption method; in said receiving unit, step for using said first synchronization code information to generate reference code information exactly equal to said verification code information in accordance with said encryption method; step for transmitting said verification code information from said transmitting unit to said receiving unit; in said receiving unit, step for comparing said verification code information received from said transmitting unit with said reference code information generated in said receiving unit; and in said transmitting unit, step for generating and transmitting second synchronization code information different from said first synchronization code information after power is interrupted and then supplied to said transmitting unit a second time. - View Dependent Claims (5)
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6. A transmitting unit for a wireless security system, comprising:
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a manually-operable switch; means having an input terminal and an output terminal, said input terminal being coupled to receive an activation signal from said switch, said means being for outputting a randomized synchronization code onto said output terminal after said means is powered up, said synchronization code being at least in part dependent on a timing of said activation signal, said means also being for outputting a rolling verification code onto said output terminal after said randomized synchronization code is output onto said output terminal; and a battery for providing power to said means for outputting. - View Dependent Claims (7)
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8. A transmitting unit for a wireless security system, comprising:
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a manually-operable switch; an integrated circuit having an input terminal and an output terminal, said input terminal being coupled to receive an activation signal from said switch, said integrated circuit outputting a randomized synchronization code onto said output terminal after said integrated circuit is powered up a first time, said integrated circuit outputting a plurality of randomized rolling verification codes onto said output terminal after said randomized synchronization code is output but before said integrated circuit is powered up a second time; and a battery for providing power to said integrated circuit. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of operation of a transmitting unit for a wireless security system, comprising the steps of:
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(a) generating a synchronization code A in said transmitting unit after power is supplied to said transmitting unit a first time but before power is supplied a second time, said synchronization code A being the first synchronization code generated in said transmitting unit after power is supplied said first time; (b) generating a plurality of randomized rolling verification codes in said transmitting unit after step (a), each of said plurality of randomized rolling verification codes being generated by causing a sequential state machine to transition a respective predetermined number of states; and (c) generating a synchronization code B in said transmitting unit after power is supplied to said transmitting unit said second time, said synchronization code B being the first synchronization code generated in said transmitting unit after power is supplied said second time, said synchronization code B being different than said synchronization code A. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A transmitting unit for a wireless security system, comprising:
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a manually-operable switch; and means having an input and an output, said input being coupled to receive an activation signal from said switch, said means being for outputting a synchronization code onto said output after said means is powered up, the value of said synchronization code being at least in part dependent on a timing of said activation signal, said means also being for outputting rolling verification codes onto said output after said synchronization code is output onto said output. - View Dependent Claims (30, 31, 32, 33)
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Specification