Personal Information Management Device, Distributed Key Storage Device, and Personal Information Management System
First Claim
1. A personal information management device that manages personal information, comprising:
- an information storage unit storing the personal information in encrypted form;
a distributed key storage unit storing a first distributed key, where the first distributed key and a second distributed key are distributed from a decryption key based on a secret sharing scheme;
a link judgment unit operable to judge whether communication is possible with a distributed key storage device storing the second distributed key;
an acquisition unit operable to, when the communication is possible, acquire the second distributed key from the distributed key storage device;
a decryption key recovering unit operable to recover the decryption key using the first and the second distributed keys based on the secret sharing scheme; and
a decryption unit operable to decrypt the encrypted personal information using the recovered decryption key.
2 Assignments
0 Petitions
Accused Products
Abstract
A personal information management device aims to save troubles of inputting passwords and deleting personal information, to prevent others from viewing the personal information, and to maintain confidentiality of the personal information even when a mobile device is lost. Personal information storage unit 201 holds encrypted personal information, key distribution unit 204 distributes a decryption key used for decrypting the encrypted personal information into a first and a second distributed keys based on a secret sharing scheme, distributed key storage unit 205 stores thereon the first distributed key, stores the second distributed key on home device 30, and deletes the decryption key. Upon decryption, link judgment unit 210 judges link establishment. Key recovery unit 207 acquires the second distributed key from home device 30, and recovers the decryption key using the first and the second distributed keys. Decryption unit 208 decrypts the encrypted personal information using the decryption key.
46 Citations
20 Claims
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1. A personal information management device that manages personal information, comprising:
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an information storage unit storing the personal information in encrypted form;
a distributed key storage unit storing a first distributed key, where the first distributed key and a second distributed key are distributed from a decryption key based on a secret sharing scheme;
a link judgment unit operable to judge whether communication is possible with a distributed key storage device storing the second distributed key;
an acquisition unit operable to, when the communication is possible, acquire the second distributed key from the distributed key storage device;
a decryption key recovering unit operable to recover the decryption key using the first and the second distributed keys based on the secret sharing scheme; and
a decryption unit operable to decrypt the encrypted personal information using the recovered decryption key. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A distributed key storage device that manages a distributed key generated based on a secret sharing scheme, comprising:
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a distributed key storage unit storing a first distributed key, where the first distributed key and a second distributed key are distributed from a decryption key used for decrypting encrypted personal information based on a secret sharing scheme;
a communication unit operable to communicate, such that a personal information management device storing the encrypted personal information judges whether communication is possible; and
a transmission unit operable to transmit the first distributed key to the personal information management device. - View Dependent Claims (12, 13, 14, 15)
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16. A personal information management system including a personal information management device that manages personal information and a distributed key storage device, the distributed key storage device comprising:
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a first distributed key storage unit storing a first distributed key, where the first distributed key and a second distributed key are distributed from a decryption key based on a secret sharing scheme;
a first link judgment unit operable to judge whether communication is possible with the personal information management device; and
a transmission unit operable to, when the communication is possible with the personal information management device, transfer the first distributed key to the personal information management device, the personal information management device comprising;
a information storage unit storing the encrypted personal information;
a second distributed key storage unit storing the second distributed key;
a second link judgment unit operable to judge whether communication is possible with the distributed key storage device;
an acquisition unit operable to, when the communication is possible with the distributed key storage device, acquire the first distributed key from the distributed key storage device;
a decryption key recovering unit operable to recover the decryption key using the first and the second distributed keys based on the secret sharing scheme; and
a decryption unit operable to decrypt the encrypted personal information using the recovered decryption key.
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17. A personal information management method used in a personal information management device storing encrypted personal information and a first distributed key, where the first distributed key and a second distributed key are distributed from a decryption key based on a secret sharing scheme, the personal information management method comprising steps of:
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judging a link whether communication is possible with a distributed key storage device storing the second distributed key;
acquiring, when the communication is possible, the second distributed key from the distributed key storage unit;
recovering the decryption key using the first and the second distributed keys based on the secret sharing scheme; and
decrypting the encrypted personal information using the recovered decryption key.
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18. A computer program used in a personal information management device storing encrypted personal information and a first distributed key, where the first distributed key and a second distributed key are distributed from a decryption key based on a secret sharing scheme, the computer program comprising steps of:
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judging a link whether communication is possible with a distributed key storage device storing the second distributed key;
acquiring, when the communication is possible, the second distributed key from the distributed key storage unit;
recovering the decryption key using the first and the second distributed keys based on the secret sharing scheme; and
decrypting the encrypted personal information using the recovered decryption key. - View Dependent Claims (19)
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20. An integrated circuit that manages personal information, comprising:
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an information storage unit storing the personal information in encrypted form;
a distributed key storage unit storing a first distributed key, where the first distributed key and a second distributed key are distributed from a decryption key based on a secret sharing scheme;
a link judgment unit operable to judge whether communication is possible with a distributed key storage device storing the second distributed key;
an acquisition unit operable to, when the communication is possible, acquire the second distributed key from the distributed key storage device;
a decryption key recovering unit operable to recover the decryption key using the first and the second distributed keys based on the secret sharing scheme; and
a decryption unit operable to decrypt the encrypted personal information using the recovered decryption key.
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Specification