Recreating a cryptographic key in a replacement device
First Claim
1. A method operational for authentication in a public cryptographic system comprising:
- creating a first private key and corresponding first public key at a mobile user device;
creating a second private key associated with the first private key and creating a second public key corresponding to the second private key at the mobile user device;
outputting the second private key from the mobile user device such that it is not stored on the mobile user device while retaining the first private key in the mobile user device, wherein outputting the second private key comprises transmitting a plurality of shares of the second private key from the mobile user device to a plurality of different entities once, such that the second private key can be re-created and used when the first private key is inaccessible;
transmitting the first public key and the second public key to a verifier device; and
using the retained first private key for authentication of the mobile user device prior to using the second private key.
1 Assignment
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Accused Products
Abstract
Embodiments describe a method and/or system whereby a secret key in a cryptographic system may be replaced without revealing the secret key. One embodiment comprises creating a first private key and corresponding first public key. A second private key associated with the first private key and a second public key corresponding to the second private key are also created. The second private key is output once such that it can be re-created and the second public key is output when outputting the first public key. The first private key is used for authentication. The method further comprises re-creating the second private key; and using the second private key for authentication. Another embodiment comprises creating a private key and corresponding public key with associated system parameter; outputting the system parameter when outputting the public key; and using the private key for authentication. The method may further comprise creating a new private key using the previous key and the system parameter.
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Citations
44 Claims
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1. A method operational for authentication in a public cryptographic system comprising:
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creating a first private key and corresponding first public key at a mobile user device; creating a second private key associated with the first private key and creating a second public key corresponding to the second private key at the mobile user device; outputting the second private key from the mobile user device such that it is not stored on the mobile user device while retaining the first private key in the mobile user device, wherein outputting the second private key comprises transmitting a plurality of shares of the second private key from the mobile user device to a plurality of different entities once, such that the second private key can be re-created and used when the first private key is inaccessible; transmitting the first public key and the second public key to a verifier device; and using the retained first private key for authentication of the mobile user device prior to using the second private key. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for verification in a public cryptographic system comprising:
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receiving a first public key from a mobile user device, wherein the first public key has a corresponding first private key stored on the mobile user device; receiving a second public key from the mobile user device, the second public key associated with the first public key, wherein the second public key has a corresponding second private key that is split into a plurality of shares that are sent to a plurality of different entities such that it is not stored on the mobile user device, where each share is sent only once and to a different entity, such that the second private key can be re-created and used when there is no access to a first private key corresponding to the first public key, wherein the first private key is disabled when the second private key is re-created and used for authentication; using the first public key for authentication of the mobile user device; and using the second public key for authentication if the first public key fails. - View Dependent Claims (12, 13)
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14. A mobile user device configured for authentication in a public cryptographic system comprising:
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means for creating a first private key and corresponding first public key at the mobile user device; means for storing the first private key at the mobile user device; means for creating a second private key associated with the first private key and creating a second public key corresponding to the second private key at the mobile user device; means for outputting the second private key from the mobile user device such that it is not stored on the mobile user device while retaining the first private key in the mobile user device, wherein outputting the second private key comprises outputting a plurality of shares of the second private key to a plurality of different entities once such that the second private key can be re-created and used when the first private key is inaccessible, wherein the first private key is disabled when the second private key is re-created and used for authentication; means for outputting the first public key and the second public key to a verifier device; and means for using the retained first private key for authentication prior to using the second private key. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A verifier apparatus configured for verification in a public cryptographic system comprising:
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means for receiving a first public key from a mobile user device, wherein the first public key has a corresponding first private key stored on the mobile user device; means for receiving a second public key from the mobile user device, the second public key associated with the first public key, wherein the second public key has a corresponding second private key that is split into a plurality of shares that are sent to a plurality of different entities such that it is not stored on the mobile user device, where each share is sent only once and to a different entity, such that the second private key can be re-created and used when there is no access to a first private key corresponding to the first public key, wherein the first private key is disabled when the second private key is re-created and used for authentication; means for storing the first public key and the second public key; means for using the first public key for authentication of the mobile user device; and means for using the second public key for authentication if the first public key fails. - View Dependent Claims (21, 22)
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23. A non-transitory machine-readable medium comprising instructions for performing a public cryptography, which when executed by a processor causes the processor to:
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create a first private key and corresponding first public key; create a second private key associated with the first private key and create a second public key corresponding to the second private key; retain the first private key and output the second private key such that it is not stored on a device where the second private key was created, the second private key being output as a plurality of shares to a plurality of different entities once such that the second private key can be re-created and used when there is no access to the first private key, wherein the first private key is disabled when the second private key is re-created and used for authentication; output the first public key and the second public key to a verifier device; and use the retained first private key for authentication prior to using the second private key for authentication. - View Dependent Claims (24, 25, 26)
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27. A non-transitory machine-readable medium comprising instructions for performing a public cryptography at a verifier device, which when executed by a processor causes the processor to:
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receive a first public key from a mobile user device, wherein the first public key has a corresponding first private key stored on the mobile user device; receive a second public key from the mobile user device, the second public key associated with the first public key, wherein the second public key has a corresponding second private key that is split into a plurality of shares that are sent to a plurality of different entities such that it is not stored on a device where the second private key was created, where each share is sent only once and to a different entity, such that the second private key can be re-created and used when there is no access to a first private key corresponding to the first public key, wherein the first private key is disabled when the second private key is re-created and used for authentication; use the first public key for authentication of the mobile user device; and use the second public key for authentication if the first public key fails. - View Dependent Claims (28, 29)
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30. A mobile user device used for authentication comprising:
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a processor configured to; generate a first private key and corresponding first public key; generate a second private key associated with the first private key; and create a second public key corresponding to the second private key; a storage medium coupled to the processor, the storage medium configured to store the first private key; and a transmitter coupled to the processor to; output the second private key such that it is not stored in the storage medium, the second private key being output as a plurality of shares to a plurality of different entities once, such that the second private key can be re-created and used when there is no access to the first private key, wherein the first private key is disabled when the second private key is re-created and used for authentication; and output the first public key and the second public key to a verifier device; wherein the processor uses the stored first private key for authentication of the mobile user device prior to using the second private key. - View Dependent Claims (31)
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32. Apparatus used for verification comprising:
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a receiver configured to receive a first public key from a mobile user device and to receive a second public key from the mobile user device, wherein the first public key has a corresponding first private key stored on the mobile user device and the second public key associated with the first public key, wherein the second public key has a corresponding second private key that is split into a plurality of shares that are sent to a plurality of different entities such that the second private key is not stored on a device where it was created, where each share is sent only once and to a different entity, such that the second private key can be re-created and used when there is no access to a first private key corresponding to the first public key, wherein the first private key is disabled when the second private key is re-created and used for authentication; a storage medium coupled to the receiver, configured to store the first and second public keys; and a processor coupled to the receiver and the storage medium, the processor configured to use the first public key for authentication of the mobile user device, the processor configured to use the second public key for authentication if the first public key fails.
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33. A method operational for authentication in a public cryptographic system, comprising:
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re-creating a second private key at a mobile user device that has no access to a first private key associated with the second private key, wherein the second private key is re-created using at least some shares of a plurality of shares of the second private key located at a plurality of different entities; creating a third private key and a corresponding third public key; outputting the third private key from the mobile user device such that it is not stored on the mobile user device while retaining the second private key at the mobile user device; and using the second private key for authentication of the mobile user device before using the third private key. - View Dependent Claims (34, 35, 36)
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37. A mobile user device adapted for authentication in a public cryptographic system, comprising:
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means for re-creating a second private key at a mobile user device that has no access to a first private key associated with the second private key, wherein the second private key is re-created using at least some shares of a plurality of shares of the second private key located at a plurality of different entities; means for creating a third private key and a corresponding third public key; means for outputting the third private key from the mobile user device such that it is not stored on the mobile user device while retaining the second private key at the mobile user device; and means for using the second private key for authentication of the mobile user device before using the third private key. - View Dependent Claims (38, 39, 40)
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41. A non-transitory machine-readable medium comprising instructions for performing a public cryptography, which when executed by a processor causes the processor to:
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re-create a second private key at a mobile user device that has no access to a first private key associated with the second private key, wherein the second private key is re-created using at least some shares of a plurality of shares of the second private key located at a plurality of different entities; create a third private key and a corresponding third public key; output the third private key from the mobile user device such that it is not stored on the mobile user device while retaining the second private key at the mobile user device; and use the second private key for authentication of the mobile user device before using the third private key. - View Dependent Claims (42, 43, 44)
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Specification