Information processing apparatus with security module

• US 20060053302A1
• Filed: 12/28/2004
• Published: 03/09/2006
• Est. Priority Date: 09/07/2004
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Yasaki, Kouichi, Yamada, Isamu, Shibata, Seiki
• Granted Patent: US 7,802,112 B2
• Time in Patent Office: Days
• US Class Current: 713/183
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/083 involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP]
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying
• CPC Class Codes: H04L 9/0897 involving additional devices, e.g. trusted platform module [TPM], smartcard or USB

Abstract

An information processing apparatus includes a TPM, a key management module for managing a key database, a memory, and a file processing module for encrypting and decrypting a file. The TPM stores a first TPM key therein and encrypts a third TPM key. The key management module stores and manages the third TPM key in the database. When the information processing apparatus starts communicating with the tamper-proof device, the key management module receives, from the TPM, a parameter for generating a second TPM key, provides the received parameter to the tamper-proof device, receives from the tamper-proof device the second TPM key which has been encrypted using the first TPM key, and provides the TPM with the second TPM key and with the third TPM key which has been encrypted using the second TPM key. When the second TPM key contains password check information, the TPM receives from the tamper-proof device a password associated with the password check information, and verifies the received password using the password check information. When it is verified that the password is correct, the TPM decrypts the second TPM key using the first TPM key, decrypts the third TPM key using the decrypted second TPM key, and decrypts, using the decrypted third TPM key, an encrypted encryption key for decrypting the file. The file processing module decrypts the file using the decrypted encryption key.

Claims

1. An information processing apparatus being adapted to communicate with a tamper-proof device, and comprising a TPM, a key management module for managing a key database, a memory, and a file processing module for encrypting and decrypting a file, wherein

said TPM stores a first TPM key therein and encrypts a third TPM key;

said key management module stores and manages the third TPM key in said database;

when said information processing apparatus starts communicating with said tamper-proof device, said key management module receives, from said TPM, a parameter for generating a second TPM key, provides the received parameter to said tamper-proof device, receives from said tamper-proof device the second TPM key which has been encrypted using the first TPM key, and provides said TPM with the second TPM key and with the third TPM key which has been encrypted using the second TPM key;

when the second TPM key contains password check information, said TPM receives from said tamper-proof device a password associated with the password check information, and verifies the received password using the password check information;

when it is verified that the password is correct, said TPM decrypts the second TPM key using the first TPM key, decrypts the third TPM key using the decrypted second TPM key, and decrypts, using the decrypted third TPM key, an encrypted encryption key for decrypting the file; and

said file processing module decrypts the file using the decrypted encryption key.

2. The information processing apparatus according to claim 1, wherein, when said tamper-proof device is coupled to said information processing apparatus, said key management module temporarily stores the second TPM key in said memory;

and

when said tamper-proof device is separated from said information processing apparatus, said key management module deletes the second TPM key stored in said memory.

3. The information processing apparatus according to claim 1, wherein, when said tamper-proof device is coupled to said information processing apparatus, said key management module stores the second TPM key in said memory;

and

when said tamper-proof device is coupled again to said information processing apparatus after said separation from said information processing apparatus, said key management module updates the second TPM key stored in said memory with a new second TPM key received from said tamper-proof device.

4. The information processing apparatus according to claim 1, wherein the third TPM key has been encrypted by said TPM using a public key of the second TPM key, and said TPM decrypts the third TPM key using a secret key of the decrypted second TPM key.

5. The information processing apparatus according to claim 1, wherein said TPM is adapted to be coupled to said tamper-proof device via a dedicated line;

and

said TPM sends, via the dedicated line to said tamper-proof device, the parameter for generating the second TPM key, and receives a password from said tamper-proof device via the dedicated line.

6. The information processing apparatus according to claim 1, wherein, when said tamper-proof device is coupled to said information processing apparatus, said TPM sends, via said key management module to said tamper-proof device, the parameter for generating the second TPM key, a signature which has been generated using a fourth TPM key, and an attribute certificate of the fourth TPM key which has been certified by a certificate authority (CA).

7. An information processing device comprising a connector for communicating with a separate information processing apparatus, a module for generating a TPM key, and a memory, wherein

said memory stores therein an encryption key, a decryption key, at least one password, and a public key of an external TPM key;

and

said generating module generates, in accordance with the password, information to be used for verifying the password, and encrypts the decryption key using the public key of the external TPM key, to thereby generate a TPM key which contains the encrypted decryption key and the information to be used for verifying the password, and said generating module is adapted to provide the generated TPM key to said separate information processing apparatus.

8. The information processing device according to claim 7, wherein said generating module of said information processing device generates a new password in accordance with a random number, generates, in accordance with the new password, information to be used for verifying the new password, and generates a TPM key which contains the information to be used for verifying the new password, the encryption key, and the encrypted decryption key.

9. The information processing device according to claim 7, wherein said information processing apparatus further comprises an apparatus identifying module, and said apparatus identifying module receives identification information of said other information processing apparatus from said other information processing apparatus, selects one password from said passwords in accordance with said identification information, and generates said TPM key which contains corresponding information which is for verification of said password thus selected.

10. The information processing device according to claim 7, wherein said generating module receives, from separate information processing apparatus, a parameter to be used for generating the second TPM key, a signature which has been generated using another TPM key, and an attribute certificate of the other TPM key which has been certified by a CA;

and

when the attribute certificate and the signature are verified to be correct, the generated TPM key is generated by said generating module.

11. In an information processing apparatus comprising a TPM, a processor and a memory and being adapted to communicate with a tamper-proof device, a method for password authentication and decrypting a TPM key, said method comprising:

storing a first TPM key in said TPM, and causing said TPM to encrypt a third TPM key;

storing and managing the third TPM key in said database;

receiving from said TPM a parameter for generating a second TPM key when said information processing apparatus starts communicating with said tamper-proof device, and providing the received parameter to said tamper-proof device, to receive from said tamper-proof device the second TPM key which has been encrypted using the first TPM key;

providing said TPM with the second TPM key and with the third TPM key which has been encrypted using the second TPM key;

receiving a password from said tamper-proof device, and causing said TPM to verify the received password using the password check information of the received second TPM key;

causing, when it is verified that the password is correct, said TPM to decrypt the third TPM key using the decrypted second TPM key, decrypt the second TPM key using the first TPM key, and decrypt, using the decrypted third TPM key, an encrypted encryption key for decrypting a file; and

decrypting the file using the decrypted encryption key.

12. In an information processing device comprising a processor, a memory and a connector for communicating with a separate information processing apparatus, said memory storing an encryption key, a decryption key, at least one password, and a public key of an external TPM key, a method comprising:

generating, in accordance with the password, information to be used for verifying the password;

encrypting the decryption key using the public key of the external TPM key;

generating a TPM key which contains the encrypted decryption key and the information to be used for verifying the password; and

providing the generated TPM key to said separate information processing apparatus.