Information processing device

• US 6,691,921 B2
• Filed: 08/14/2002
• Issued: 02/17/2004
• Est. Priority Date: 11/16/2001
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd., Hitachi ULSI Systems Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd., Hitachi ULSI Systems Company Limited (Hitachi, Ltd.)
• Inventors: Watanabe, Takashi, Endo, Takashi, Tsukamoto, Takashi, Kaminaga, Masahiro, Nakada, Kunihiko
• Primary Examiner(s): Lee, Michael G.
• Assistant Examiner(s): NGUYEN, KIMBERLY D
• Application Number:
  US10/217,565
• Publication Number:
  US 20030094499A1
• Time in Patent Office: 552 Days
• Field of Search: 235/492, 235/380, 235/382, 235/375, 235/383, 380/46, 380/47, 380/30, 380/21, 713/172, 713/189, 713/193, 713/194
• US Class Current: 235/492
• CPC Class Codes: G06F 21/72 in cryptographic circuits
• CPC Class Codes: G06F 21/755 with measures against power attack
• CPC Class Codes: G06F 2207/7219 Countermeasures against side channel or fault attacks
• CPC Class Codes: G06F 7/48 using non-contact-making devices, e.g. tube, solid state device; using unspecified devices
• CPC Class Codes: G06F 7/501 Half or full adders, i.e. basic adder cells for one denomination
• CPC Class Codes: H04L 9/002 Countermeasures against attacks on cryptographic mechanisms network architectures or network communication protocols for protection against malicious traffic H04L63/1441
• CPC Class Codes: H04L 9/0861 Generation of secret information including derivation or calculation of cryptographic keys or passwords
• CPC Class Codes: H04L 9/0894 Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage

Abstract

An object of the present invention is to prevent secret information that is being internally processed from being inferred through operational information of a secured device, including the current consumption information. One solution is provided by an information processing device having at least a key generation apparatus that generates key data automatically, an encryption unit that encrypts data with the corresponding key data, a register that stores a plurality of encrypted data items with the corresponding encryption key data items, and an arithmetic unit that performs operations using data expressed with the corresponding encryption key data and new key data as the input, encrypts the operation result with new input key data, and outputs the result, thereby being capable of performing internal processing on an encrypted data expression. Accordingly, only encrypted data is transferred on the internal or external data bus line.

Claims

1. An integrated circuit card comprising:

an arithmetic unit; and

a key generator, wherein

said key generator generates unpredictably different key data as time goes by, said arithmetic unit calculates based upon first data, which data structure includes first key data and first encrypted data, to generate and output a second data which data structure is identical with the data structure of said first data and includes second key data and second encrypted data,

each of said first and second key data is one of said different key data,

said first and second encrypted data are encrypted with a cryptographic algorithm by use of said first key data and said second key data respectively, and

wherein said key generator and said arithmetic unit are provided within a central processing unit to prevent data encrypted therein from being inferred through operational information thereof.

2. The integrated circuit card according to claim 1, wherein the first data is decrypted with said first key data before input into the arithmetic unit, and said second encrypted data is encrypted by the arithmetic unit with said second key data.

3. The integrated circuit card according to claim 2, wherein the arithmetic unit processes the first data according to a truth table which defined a relation between input data and output data of the arithmetic unit.

4. The integrated circuit card according to claim 3, wherein the output data of said arithmetic unit is encrypted with said truth table.

5. The integrated circuit card according to claim 1, wherein the arithmetic unit is an adder.

6. The integrated circuit card according to claim 1, further comprising transfer means for transferring said first data, wherein the transfer means comprises a data bus line.

7. The integrated circuit card according to claim 1, further comprising a memory unit,

wherein the memory unit comprises at least one of a register, a ROM/EEPROM, and a RAM for storing said first data.

8. The integrated circuit card according to claim 1, further comprising an instruction decoder for interpreting and executing said first data including decrypting means for decrypting said first data into said original data, wherein said original data are instructions of the arithmetic unit.

9. The integrated circuit card according to claim 1, further comprising an instruction decoder for interpreting and executing said first data through a correspondence table, wherein the correspondence table records a many-to-one correspondence between the first data and original instructions of the arithmetic unit.

10. The integrated circuit cart according to claim 9, wherein the instructions of the arithmetic unit are coded as instruction codes in the correspondence table.

11. The integrated circuit card according to claim 10, wherein each of the instruction codes is encrypted with a 1-bit key.

12. The integrated circuit card according to claim 1, further comprising:

a decoder; and

a memory unit, wherein the memory unit comprises at least one of ROM/EEPROM and RAM for storing the first data to be transferred by the transfer means then decoded byte decoder.

13. The integrated circuit card according to claim 1, further comprising:

an encoder;

a decoder;

a memory unit; and

a transfer means for transferring the first data into/from the memory unit;

wherein the memory unit comprises ROM/EEPROM for storing true data to be encrypted by the encoder then transferred by the transfer means, and RAM for storing the first data to be transferred by the transfer means then decoded by the decoder.

14. The integrated circuit card according to claim 1, further comprising:

a decoder for decoding the first data; and

encryption means for encrypting output from the decoder with a second cryptographic algorithm, converting the output into second data including key data and encrypted data to be stored in at least one of ROM/EEPROM and RAM of the memory unit.

15. The integrated circuit card according to claim 1, further comprising second encryption means for encrypting the first data with a second cryptographic algorithm thereby converting the first data into the second data to be stored in a memory unit.

16. The integrated circuit card according to claim 1, said first and second encrypted data are encrypted with a Vernam cipher.

17. The integrated circuit card according to claim 1, wherein the arithmetic unit comprising:

a decoder for decrypting said first data into decrypted data by use of said first key data;

an arithmetic logical unit for processing said decrypted data and outputting the processed data; and

an encoder for encrypting said processed data Into said second data by use of said second key data.

18. An integrated circuit card comprising:

an arithmetic unit;

first encryption means for encrypting data to be input into the arithmetic unit into first data including first key data and first encrypted data;

one decoder for decrypting the first data;

one encoder for unpredictably encrypting output of the arithmetic unit into second data including second key data and second encrypted data as time goes by; and

transfer means for transferring only encrypted data into/from the arithmetic unit, wherein,

the decoder is disposed to an input of the arithmetic unit, and

the encoder is disposed to an output of the arithmetic unit,

wherein the arithmetic unit, the first encryption means, the decoder, and the encoder are provided within a central processing unit to prevent data encrypted therein from being inferred through operational information thereof.

19. An integrated circuit card comprising:

a memory unit;

an arithmetic unit;

first encryption means for encrypting data written into/read from the man my unit or data input into/output from the arithmetic unit with a first cryptographic algorithm into first data including first key data and first encrypted data; and

second encryption means for unpredictably encrypting as time goes by the first data with a second cryptographic algorithm into second data including second key data and second encrypted data to be stored in at least one of ROM/EEPROM and RAM of the memory unit,

wherein said arithmetic unit, said first encryption means, and said second encryption means are provided within a central processing unit to prevent data encrypted therein from being inferred through operational information thereof.