Granted Patent B2

US 8,161,295 · App. 11/091,364 · Granted Apr 17, 2012

Abstract

Claims (62)

1. A method for use by an electronic device of a mobile communication system, comprising

providing the electronic device with an identification card equipped with a cryptographic algorithm;

generating at least one seed value in the electronic device;

transmitting said at least one seed value to the identification card;

receiving at least one derived value from the identification card generated by the cryptographic algorithm with said at least one seed value as an input;

using said at least one derived value for producing an encryption key in said electronic device;

encrypting data to be stored with the encryption key to form encrypted data; and

storing said at least one seed value and an individual identification in connection with the encrypted data;

wherein a device-specific identification is stored in the electronic device, and wherein the device-specific identification of the electronic device is also used for the formation of said encryption key.

2. The method according to claim 1 , wherein the identification card is provided with an internal key, wherein said internal key is also used in the formation of said encryption key.

3. The method according to claim 2 , wherein in the formation of said encryption key, a unidirectional function is used, said at least one derived value and said internal key being used as the input.

4. The method according to claim 2 , wherein for decrypting the data in a data group, a decryption key is formed, for whose formation the data of the data group is searched for data about at least one seed value used in the encryption step, said at least one seed value is transmitted to the identification card, in which said cryptographic algorithm is performed, said seed value and said internal key being used as the input, wherein in the cryptographic algorithm, at least one of said at least one derived value is formed, and said at least one derived value is transmitted to the electronic device, wherein said at least one derived value is used for producing said decryption key.

5. The method according to claim 4 , wherein the electronic device is provided with two or more stored data groups, and each data group is provided with stored information about an individual identifier, wherein at the stage of decryption of the data, said data groups are searched for the data group whose individual identifier matches with the internal key stored on the identification card, and if the data group was found, the data of the found data group is decrypted.

6. The method according to claim 1 , wherein the identification card used is an identification card used for identifying mobile stations of a mobile communication system, wherein said cryptographic algorithm used is the algorithm used for identifying a mobile station.

7. The method according to claim 1 , wherein the identification card used is at least one of the following:

a subscriber identity module card,

a USIM card,

an R-UIM card,

an electronic identification card,

a bank card,

a credit card.

8. The method according to claim 1 , wherein at least a part of the seed value is formed in a random or pseudo random way.

9. An electronic device of a mobile communication system, comprising a memory and an identification card connection and provided with an identification card equipped with a cryptographic algorithm, wherein the electronic device is configured to generate at least one seed value, to transmit said at least one seed value to the identification card, said identification card is configured to perform said cryptographic algorithm, said at least one seed value is arranged to be used as an input, wherein in the cryptographic algorithm, at least one derived value is arranged to be formed, and the electronic device is configured to receive said at least one derived value and to use said at least one derived value in the formation of said encryption key, configured to encrypt data with the encryption key to form encrypted data; configured to store the encrypted data, and configured to store said at least one seed value and an individual identification in connection with the encrypted data, wherein an equipment specific identification is stored in the electronic device, wherein the equipment specific identification of the electronic device is also configured to be used in the formation of said encryption key.

10. The electronic device according to claim 9 , wherein the identification card is provided with an internal key, wherein said internal key is also arranged to be used in the formation of said encryption key.

11. The electronic device according to claim 10 , wherein in the formation of said encryption key, a unidirectional function is configured to be used, said at least one derived value and said internal key being used as the input.

12. The electronic device according to claim 10 , wherein it is configured to form a decryption key to be used in the decryption of data of a data group, to search the data of the data group for data about at least one seed value used at the encryption stage, to transmit said at least one seed value to the identification card in which said cryptographic algorithm is arranged to be performed, said at least one seed value and said internal key being arranged to be used as the input, wherein at least one of said at least one derived value is arranged to be used in the algorithm, wherein the device is configured to receive said at least one derived value from the identification card, wherein said at least one of said at least one derived value is configured to be used in the formation of said decryption key.

13. The electronic device according to claim 12 , wherein two or more data groups are stored in the device, and data about the internal key is stored in connection with each data group, wherein the device is configured to search said data groups for the data group whose individual identifier matches with the internal key stored on the identification card, to decrypt the data of the data group.

14. The electronic device according to claim 9 , wherein the identification card is an identification card used for identifying mobile stations of a mobile communication system, wherein said cryptographic algorithm is the algorithm used for identifying a mobile station.

15. The electronic device according to claim 9 , wherein the identification card is one of the following:

a subscriber identity module card,

a USIM card,

an R-UIM card,

an electronic identification card,

bank card,

a credit card.

16. A control block configured to control at least one function of an electronic device of a mobile communication system, which electronic device comprises an identification card connection and is provided with an identification card equipped with a cryptographic algorithm, wherein the control block comprises

a seed generator configured to generate at least one seed value,

an output configured to transmit said at least one seed value to the identification card, an input configured to receive at least one derived value generated by said identification card by said cryptographic algorithm by using said seed value as an input to form at least one derived value, and

a key generator configured to use said at least one derived value in the formation of said encryption key, and

an encrypting element configured to encrypt data with the encryption key to form encrypted data; wherein the control block is configured to store the encrypted data, and configured to store at least one seed value and an individual identification in connection with the encrypted data;

wherein a device-specific identification is stored in the electronic device, and wherein the device-specific identification of the electronic device is also used for the formation of said encryption key.

17. A computer readable medium having application software embodied therein for use in an electronic device of a mobile communication system which comprises machine-executable program commands stored on a readable medium for execution by a processor, the machine-executable program commands:

for encrypting data to be stored with an encryption key to form encrypted data, and

for storing at least one seed value and an individual identification in connection with the encrypted data in a memory of the electronic device,

and which electronic device is provided with an identification card equipped with a cryptographic algorithm, wherein the application software comprises machine executable program commands:

for generating at least one seed value,

for searching the data of a data group for information about said at least one seed value used at the encryption stage,

for transmitting said at least one seed value to the identification card in which said cryptographic algorithm is arranged to be used, said at least one seed value being arranged to be used as an input, wherein at least one derived value is arranged to be formed in the algorithm,

wherein the application software comprises machine-executable program commands:

for receiving said at least one derived value from the identification card, and

for using said at least one derived value in the formation of said decryption key;

wherein a device-specific identification is stored in the electronic device, and

wherein the device-specific identification of the electronic device is also used for the formation of said encryption key.

18. The computer readable medium according to claim 17 , wherein for decrypting the data of the data group, the application software comprises machine executable program commands:

for searching the data of the data group for information about said at least one seed value used at the encryption stage,

for transmitting said at least one seed value to the identification card, in which said cryptographic algorithm is used, said at least one seed value being used as the input, wherein at least one derived value is formed in the algorithm,

wherein the application software comprises machine-executable program commands:

for receiving said at least one derived value from the identification card, and

for using at least one of said at least one derived value in the formation of said decryption key, and

for decrypting the data group with said decryption key.

19. The computer readable medium according to claim 18 , wherein the electronic device is provided with two or more stored data groups, and each data group is provided with stored information about an internal key, wherein the application software comprises machine executable program commands for searching said data groups for the data group whose individual identifier matches with the internal key stored on the identification card, and if the data group is found, the data of the found data group is decrypted.

20. An electronic device of a mobile communication system, comprising a memory and an identification card connection and provided with an identification card equipped with a cryptographic algorithm, wherein the electronic device comprises means for generating at least one seed value, means for transmitting said at least one seed value to the identification card equipped with means for performing said cryptographic algorithm, said at least one seed value arranged to being used as an input, wherein in the cryptographic algorithm, at least one derived value is arranged to be formed, and the electronic device comprises means for receiving said at least one derived value and means for using said at least one derived value in the formation of said encryption key, means for encrypting data with the encryption key to form encrypted data and means for storing the encrypted data, and said at least one seed value and an individual identification in connection with the encrypted data, wherein a device-specific identification is stored in the electronic device, and wherein the device-specific identification of the electronic device is also used for the formation of said encryption key.

Assignments (10)