Method and system of reconstructing a secret code in a vehicle for performing secure operations
First Claim
1. A method for constructing a secret code in a processing unit when in communication with a portable security unit, wherein the processing unit and portable security unit each contain respective volatile and non-volatile memory, and wherein the processing unit uses the security code to perform a secure operation, the method comprising the steps of:
- linking the portable security unit with the processing unit;
exchanging mutual authentication messages between the portable security unit and the processing unit as a condition to continuing the method;
communicating a first portion of the secret code stored in the non-volatile memory of the portable security unit to the processing unit;
combining a second portion of the secret code stored in the non-volatile memory of the processing unit with the first portion of the secret code;
storing at least the first portion of the secret code in a volatile memory of the processing unit;
performing the secure operation using the secret code;
splitting the combined secret code into two parts and storing a first part in the non-volatile memory of the portable security unit and a second part in the non-volatile memory of the processing unit;
de-linking the portable security unit from the processing unit, the first part of the secret code being stored in the non volatile memory of the portable security unit prior to de-linking the portable security unit from the processing unit; and
deleting at least a portion of the secret code from the volatile memory of the processing unit.
3 Assignments
0 Petitions
Accused Products
Abstract
A method is provided for constructing a secret code in a processing unit when in communication with a portable security unit. Mutual authentication messages are exchanged between a linked portable security unit and processing unit. A first portion of the secret code is communicated to the processing unit. The processing unit combines the first portion and a second portion of the secret code stored in the non-volatile memory of the processing unit. The secret code is stored in a volatile memory of the processing unit. A secure operation is performed using the secret code. The portable security unit is de-linked from the processing unit. At least a portion of the secret code is deleted from the volatile memory of the processing unit.
28 Citations
23 Claims
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1. A method for constructing a secret code in a processing unit when in communication with a portable security unit, wherein the processing unit and portable security unit each contain respective volatile and non-volatile memory, and wherein the processing unit uses the security code to perform a secure operation, the method comprising the steps of:
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linking the portable security unit with the processing unit; exchanging mutual authentication messages between the portable security unit and the processing unit as a condition to continuing the method; communicating a first portion of the secret code stored in the non-volatile memory of the portable security unit to the processing unit; combining a second portion of the secret code stored in the non-volatile memory of the processing unit with the first portion of the secret code; storing at least the first portion of the secret code in a volatile memory of the processing unit; performing the secure operation using the secret code; splitting the combined secret code into two parts and storing a first part in the non-volatile memory of the portable security unit and a second part in the non-volatile memory of the processing unit; de-linking the portable security unit from the processing unit, the first part of the secret code being stored in the non volatile memory of the portable security unit prior to de-linking the portable security unit from the processing unit; and deleting at least a portion of the secret code from the volatile memory of the processing unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A vehicle security system comprising:
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a processing unit for constructing a secret code, the processing unit having a non-volatile memory and a volatile memory; and a portable security unit for linking to the processing unit, the portable security unit communicating with the processing unit for performing mutual authentication between the portable security unit and the processing unit in response to being linked to one another, the portable security unit having a non-volatile memory for storing a first portion of the secret code; wherein the first portion of the secret code is communicated to the processing unit in response to a successful mutual authentication between the portable security unit and the processing unit, wherein the first portion of the secret code is combined with a second portion of the secret code stored in the non-volatile memory of the processing unit, wherein a secure operation is performed using the secret code, wherein the combined secret code is split into two parts, wherein a first part is stored in the non-volatile memory of the portable security unit and a second part in the non-volatile memory of the processing unit, and wherein the first part of the secret code is stored in the non volatile memory of the portable security unit prior to de-linking the portable security unit from the processing unit. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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Specification