Firmware encrypting and decrypting method and an apparatus using the same

• US 7,929,692 B2
• Filed: 01/07/2005
• Issued: 04/19/2011
• Est. Priority Date: 01/09/2004
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, In-Koo, Lee, Jong-gyou
• Primary Examiner(s): Dada, Beemnet W
• Assistant Examiner(s): Schwartz, Darren B
• Application Number:
  US11/030,104
• Publication Number:
  US 20050154912A1
• Time in Patent Office: 2,293 Days
• Field of Search: 380277-280, 380/286, 380 44- 47, 713164-167, 713187-190, 713/193, 726 26- 27, 726/30
• US Class Current: 380/44
• CPC Class Codes: G06F 21/72 in cryptographic circuits

Abstract

A method of encrypting and decrypting a firmware used in electronic devices and an apparatus using the same. The firmware encryption method includes, receiving a predetermined special key data; generating an encryption key data from the predetermined special key data using a predetermined random number; generating an encryption data corresponding to firmware address information to be stored to a memory based on the encryption key data; and generating an encrypted firmware data by performing an XOR operation on the encryption data and firmware data to be stored in the firmware address.

Claims

1. A firmware encryption method, comprising:

receiving predetermined special key data;

generating an encryption key from the predetermined special key data using a predetermined random number generating process at an encryption key generator;

generating encryption data by selecting some bits and not all bits of the encryption key according to firmware address information at a firmware encryption processing unit; and

generating encrypted firmware data by performing an XOR operation on the encryption data and firmware data to be stored in a memory corresponding to the firmware address information, at the firmware encryption processing unit.

2. The method according to claim 1, wherein the encryption key is composed of N bytes of the firmware data, and N is a predetermined integer.

3. The method according to claim 1, wherein the encryption data is generated by selecting one byte from N bytes of the encryption key according to values of predetermined bits of the firmware address information.

4. A firmware decryption method, comprising:

reading predetermined special key data stored in a memory upon determining that a condition to operate the firmware is satisfied;

generating an encryption key based on the predetermined special key data at an encryption key generator;

generating encryption data by selecting some bits and not all bits of the encryption key according to firmware address information at a firmware decryption processing unit; and

generating decrypted firmware data by performing an XOR operation on the encryption data and firmware data stored in the memory corresponding to the firmware address information, at the firmware decryption processing unit.

5. The method according to claim 4, wherein the encryption key is composed of N bytes of the firmware data, and N is a predetermined integer.

6. The method according to claim 4, wherein the encryption data is generated by selecting a byte from N bytes of the encryption key according to values of predetermined bits of the firmware address information.

7. A firmware encryption apparatus, comprising:

an encryption key generator generating an encryption key from a predetermined input special key data using a predetermined random number generating process; and

a firmware encryption processing unit generating encryption data by selecting some bits and not all bits of the encryption key according to firmware address information and generating encrypted firmware data by performing an XOR operation on the encryption data and firmware data to be stored in a memory corresponding to the firmware address information.

8. The apparatus according to claim 7, wherein the encryption key is composed of N bytes of the firmware data, and N is a predetermined integer.

9. The apparatus according to claim 7, wherein the encryption data is generated by selecting one byte from N bytes of the encryption key according to values of predetermined bits of the firmware address information.

13. The apparatus according to claim 7, wherein the predetermined special key data received by the encryption key generator is transmitted from an external device.

14. The apparatus according to claim 13, wherein the encryption key generator receives a 256 bit special key data as the predetermined special key data, and generates a 32 bit data as the encryption key data.

15. The apparatus according to claim 14, wherein the 32 bit data generated as the encryption key includes an 8 bit data as the firmware data and a 16 bit data as the firmware address information.

16. The apparatus according to claim 15, wherein the encryption data generated by the firmware encryption processing unit is based on lowest 2 bits of the firmware address.

17. The apparatus according to claim 7, further comprising:

a ROM writer to write the encrypted firmware data to a memory.

10. A firmware decryption apparatus comprising:

a memory storing encrypted firmware and predetermined special key data;

a microprocessor reading the predetermined special key data from the memory upon determining that a condition to operate the firmware is satisfied, generating firmware address information to read the encrypted firmware from the memory and a read control signal and executing a program included in the encrypted firmware;

an encryption key generator generating an encryption key from the predetermined special key data using a predetermined random number generating process; and

a firmware decryption processing unit generating encryption data by selecting some bits and not all bits of the encryption key according to firmware address information and generating decrypted firmware data by performing an XOR operation on the encryption data and the encrypted firmware data stored in the memory corresponding to the firmware address information.

11. The apparatus according to claim 10, wherein the encryption key is composed of N bytes of the firmware data, and N is a predetermined integer.

12. The apparatus according to claim 10, wherein the encryption data is generated by selecting a byte from N bytes of the encryption key according to values of predetermined bits of the firmware address information.

18. A method to encrypt firmware data of an electronic device, comprising:

generating encryption data by selecting some bits and not all bits of an encryption key according to firmware address information at a firmware encryption processing unit, the encryption key being generated from predetermined special key data using a random number generating process; and

encrypting the firmware data by performing an XOR operation on the encryption data and the firmware data to be stored in a memory corresponding to the firmware address information, at the firmware encryption processing unit, and storing the encrypted firmware data to the address in memory.

19. The method according to claim 18, wherein the encryption data is generated by selecting one byte from N bytes of the encryption key according to values of predetermined bits of the address in the memory.

20. A method to decrypt encrypted firmware data of an electronic device, comprising:

generating an encryption key using predetermined special key data stored in a memory upon determining that a condition to use the encrypted firmware data is satisfied at an encryption key generator;

generating encryption data by selecting some bits and not all bits of an encryption key according to firmware address information at a firmware decryption processing unit; and

decrypting the encrypted firmware data by performing an XOR operation on the generated encryption data and the encrypted firmware data stored in the memory corresponding to the firmware address information, at the firmware decryption processing unit.

21. The method according to claim 20, wherein the encryption key is composed of predetermined bytes of the firmware data.

22. A non-transitory computer readable medium recorded with a program to cause a processor to execute a firmware encryption operation, the operation comprising:

generating encryption data corresponding to an address in a memory based on some bits and not all bits of an encryption key generated from a predetermined special key data using a random number generating process; and

encrypting the firmware data by performing an XOR operation on the encryption data and the firmware data to be stored in the memory corresponding to the address, and storing the encrypted firmware data to the address in memory.

23. A non-transitory computer readable medium recorded with a program to cause a processor to execute a firmware decryption operation, the operation comprising:

generating an encryption key using predetermined special key data stored in a memory upon determining that a condition to use encrypted firmware data is satisfied;

generating encryption data by selecting some bits and not all bits of the encryption key according to firmware address information; and

decrypting the encrypted firmware data by performing an XOR operation on the generated encryption data and the encrypted firmware data stored in the memory corresponding to the firmware address information.