US 7,681,030 B2Granted

Mobile communication terminal, information processing method, data processing program, and recording medium

AssigneeNtt Docomo, Inc.

InventorsMotoyuki Uchida, Tadao Takami, Yasutaka Urakawa, Takashi Kadohiro, Hiroaki Tomoda, Seiji Hoshi, Makoto Ito

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Abstract

A transmitter cell phone 10 is provided with a controller 11 for fulfilling functions of a data encryptor, a first key encryptor, and an encryption file generator. The data encryptor encrypts data, using a first encryption key. The first key encryptor encrypts the first encryption key, using a second encryption key. The encryption file generator generates an encryption file of the data from the data encrypted by the data encryptor, the first encryption key encrypted by the first key encryptor, and user-specific information permitting identification of a user of the mobile communication terminal.

Claims4

Dependent claims

A mobile communication terminal having a user associated therewith comprising:

a controller;
a data encrypting unit configured to encrypt data using a first encryption key;
a second key generating unit configured to generate a second encryption key using a pre-determined algorithm and user-specific information permitting identification of the user associated with the mobile communication terminal;
a first falsification check data generating unit configured to generate first falsification check data used for a falsification check on the data;
an additional information encrypting unit configured to encrypt, using the second encryption key, additional information containing the generated first falsification check data;
an encryption file generating unit configured to generate an encryption file comprising the encrypted data, the encrypted additional information, and the user-specific information permitting identification of the user associated with the mobile communication terminal used to generate the second encryption key;
a transferring unit configured to transfer the generated encryption file including the encrypted data, the encrypted additional information, and the user-specific information to a receiver mobile communication terminal storing the pre-determined algorithm;
a data acquiring unit configured to acquire the encrypted data, the encrypted additional information, and a second encryption key information from the encryption file;
a second key generating unit configured to generate the second encryption key using the acquired second encryption key information;
an additional information decrypting unit configured to decrypt the additional information using the generated second encryption key;
a first encryption key information acquiring unit configured to acquire a first encryption key information and the first falsification check data from the decrypted additional information;
a first key generating unit configured to generate the first encryption key using the acquired first encryption key information;
and
a data decrypting unit configured to decrypt the acquired encrypted data using the generated first encryption key,
wherein the receiver mobile communication terminal is able to decrypt the encrypted data by using the encrypted additional information, the user-specific information and the pre-determined algorithm,
wherein an encryption key information contains identification information for identification of an algorithm used in generation of the second encryption key,
wherein the second key generating unit is further configured to generate the second encryption key using the algorithm identified by the identification information, and
wherein the additional information contains a data list and first encryption key information necessary for generation of the first encryption key.

15 more elements

An information processing method for a mobile communication terminal having a user associated therewith to process data, said information processing method comprising:

encrypting data using a first encryption key;
generating second encryption key using a pre-determined algorithm and user-specific information permitting identification of the user associated with the mobile communication terminal;
generating first falsification check data used for a falsification check on the data;
encrypting additional information containing the first falsification check data generated in the first falsification check data generation step, using the second encryption key;
generating an encryption file comprising the encrypted data, the encrypted additional information, and the user-specific information permitting identification of the user associated with the mobile communication terminal used to generate the second encryption key;
transferring the generated encryption file including the encrypted data, the encrypted additional information, and the user-specific information to a receiver mobile communication terminal storing the pre-determined algorithm;
decrypting, at the receiver mobile communication terminal, the encrypted data using the encrypted additional information, the user-specific information and the pre-determined algorithm;
acquiring the encrypted data, the encrypted additional information, and a second encryption key information from the encryption file;
generating the second encryption key using the acquired second encryption key information;
decrypting the additional information using the generated second encryption key;
acquiring a first encryption key information and the first falsification check data from the decrypted additional information;
generating the first encryption key using the first encryption key information acquired in the prior acquiring step;
and
a data decryption step of decrypting the acquired encrypted data using the generated first encryption key,
wherein an encryption key information contains identification information for identification of an algorithm used in generating the second encryption key,
wherein the generating second encryption key further generates the second encryption key using the algorithm identified by the identification information, and
wherein the additional information contains a data list and first encryption key information necessary for generating the first encryption key.

14 more elements

A computer readable storage medium including a data processing program for executing a method for a mobile communication terminal having a user associated therewith to process data, the method comprising:

encrypting data using a first encryption key;
generating second encryption key using a pre-determined algorithm and user-specific information permitting identification of the user associated with the mobile communication terminal;
generating first falsification check data used for a falsification check on the data;
encrypting additional information containing the first falsification check data generated in the first falsification check data generation step, using the second encryption key;
generating an encryption file comprising the encrypted data, the encrypted additional information, and the user-specific information permitting identification of the user associated with the mobile communication terminal used to generate the second encryption key;
transferring the generated encryption file including the encrypted data, the encrypted additional information, and the user-specific information to a receiver mobile communication terminal storing the pre-determined algorithm;
decrypting, at the receiver mobile communication terminal, the encrypted data using the encrypted additional information, the user-specific information and the pre-determined algorithm;
acquiring the encrypted data, the encrypted additional information, and a second encryption key information from the encryption file;
generating the second encryption key using the acquired second encryption key information;
decrypting the additional information using the generated second encryption key;
acquiring a first encryption key information and the first falsification check data from the decrypted additional information;
generating the first encryption key using the acquired first encryption key information;
and
decrypting the acquired data using the generated first encryption key,
wherein an encryption key information contains identification information for identification of an algorithm used in generating the second encryption key,
wherein the generating second encryption key further generates the second encryption key using the algorithm identified by the identification information, and
wherein the additional information contains a data list and first encryption key information necessary for generating the first encryption key.

14 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/482,169Filed 7 Feb 2003
Priority: JP 2002-0329478 Feb 2002
Published: US 2004/0171399 A12 Sep 2004
Granted: 16 Mar 2010
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H04L 9/0866
Generation of secret information including derivation or calculation of cryptographic keys or passwords: involving user or device identifiers,…
H04L 9/0822
Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely…: using…
H04W 12/033
Protecting confidentiality, e.g. by encryption: of the user plane, e.g. user's traffic
H04L 2209/56
Additional information or applications relating to cryptographic mechanisms or cryptographic arrangements for secret or secure communication…