Rendering and encryption engine for application program obfuscation

• US 20050069131A1
• Filed: 09/25/2003
• Published: 03/31/2005
• Est. Priority Date: 09/25/2003
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: de Jong, Eduard K.
• Granted Patent: US 8,220,058 B2
• Time in Patent Office: Days
• US Class Current: 380/239
• CPC Class Codes: G06F 21/14 against software analysis or reverse engineering, e.g. by obfuscation
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: H04L 2209/16 Obfuscation or hiding, e.g. involving white box
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 9/065 Encryption by serially and continuously modifying data stream elements, e.g. stream cipher systems, RC4, SEAL or A5/3
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/25816 involving client authentication restricting access to computer systems by authenticating users using a predetermined code G06F21/33; cryptographic authentication protocols H04L9/32; networks authentication protocols H04L63/08; authentication in wireless network security H04W12/06
• CPC Class Codes: H04N 21/41407 embedded in a portable device, e.g. video client on a mobile phone, PDA, laptop constructional details of equipment or arrangements specially adapted for portable computer application G06F1/1626; arrangements specially adapted for mobile receivers in broadcast systems H04H20/57
• CPC Class Codes: H04N 21/42684 Client identification by a unique number or address, e.g. serial number, MAC address, socket ID network arrangements, protocols or services for addressing or naming H04L61/00
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/6581 Reference data, e.g. a movie identifier for ordering a movie or a product identifier in a home shopping application
• CPC Class Codes: H04N 21/8173 End-user applications, e.g. Web browser, game
• CPC Class Codes: H04N 7/165 Centralised control of user terminal subsequent to an upstream request signal H04N7/17345; Registering at central by two-way working H04N7/17309
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

Obfuscation of an application program comprises receiving an obfuscated key decryption program comprising an instruction stream configured to perform a decryption algorithm for a first cryptographic key. The obfuscated key decryption program also has an encrypted second cryptographic key scrambled in its instruction stream. The second cryptographic key is encrypted with the first cryptographic key. The obfuscated key decryption program is executed to decrypt the second cryptographic key. The second cryptographic key is used for decrypting digital content.

Claims

1. A method for application program obfuscation, comprising:

receiving a reference to a decryption algorithm and a first cryptographic key;

creating a key decryption program comprising an instruction stream, said key decryption program configured to perform said decryption algorithm for said first cryptographic key;

applying a cryptographic process to a second cryptographic key together with said first cryptographic key to create an encrypted second cryptographic key;

scrambling said encrypted second cryptographic key into said instruction stream using a code obfuscation method indicated by an obfuscation descriptor, said scrambling creating an obfuscated key decryption program, said obfuscation descriptor based at least in part on a target ID; and

sending said obfuscated key decryption program.

2. The method of claim 1, further comprising sending digital content protected by said second cryptographic key.

3. The method of claim 2, further comprising sending said obfuscated key decryption program together with said digital content.

4. The method of claim 1 wherein said target ID comprises a VM ID.

5. A method for application program obfuscation, comprising:

receiving an obfuscated key decryption program comprising an instruction stream configured to perform a decryption algorithm for a first cryptographic key, said obfuscated decryption program having an encrypted second cryptographic key scrambled in said instruction stream, said second cryptographic key encrypted with said first cryptographic key;

executing said program to decrypt said second cryptographic key; and

decrypting digital content using said second cryptographic key.

6. A program storage device readable by a machine, embodying a program of instructions executable by the machine to perform a method for application program obfuscation, the method comprising:

receiving a reference to a decryption algorithm and a first cryptographic key;

creating a key decryption program comprising an instruction stream, said key decryption program configured to perform said decryption algorithm for said first cryptographic key;

applying a cryptographic process to a second cryptographic key together with said first cryptographic key to create an encrypted second cryptographic key;

scrambling said encrypted second cryptographic key into said instruction stream using a code obfuscation method indicated by an obfuscation descriptor, said scrambling creating an obfuscated key decryption program, said obfuscation descriptor based at least in part on a target ID; and

sending said obfuscated key decryption program.

7. The program storage device of claim 6, said method further comprising sending digital content protected by said second cryptographic key.

8. The program storage device of claim 7, said method further comprising sending said obfuscated key decryption program together with said digital content.

9. The program storage device of claim 6 wherein said target ID comprises a VM ID.

10. A program storage device readable by a machine, embodying a program of instructions executable by the machine to perform a method for application program obfuscation, the method comprising:

receiving an obfuscated key decryption program comprising an instruction stream configured to perform a decryption algorithm for a first cryptographic key, said obfuscated decryption program having an encrypted second cryptographic key scrambled in said instruction stream, said second cryptographic key encrypted with said first cryptographic key;

executing said program to decrypt said second cryptographic key; and

decrypting digital content using said second cryptographic key.

11. An apparatus for application program obfuscation, comprising:

means for receiving a reference to a decryption algorithm and a first cryptographic key;

means for creating a key decryption program comprising an instruction stream, said key decryption program configured to perform said decryption algorithm for said first cryptographic key;

means for applying a cryptographic process to a second cryptographic key together with said first cryptographic key to create an encrypted second cryptographic key;

means for scrambling said encrypted second cryptographic key into said instruction stream using a code obfuscation method indicated by an obfuscation descriptor, said scrambling creating an obfuscated key decryption program, said obfuscation descriptor based at least in part on a target ID; and

means for sending said obfuscated key decryption program.

12. The apparatus of claim 11, further comprising means for sending digital content protected by said second cryptographic key.

13. The apparatus of claim 12, further comprising means for sending said obfuscated key decryption program together with said digital content.

14. The apparatus of claim 11 wherein said target ID comprises a VM ID.

15. An apparatus for application program obfuscation, comprising:

means for receiving an obfuscated key decryption program comprising an instruction stream configured to perform a decryption algorithm for a first cryptographic key, said obfuscated decryption program having an encrypted second cryptographic key scrambled in said instruction stream, said second cryptographic key encrypted with said first cryptographic key;

means for executing said program to decrypt said second cryptographic key; and

means for decrypting digital content using said second cryptographic key.

16. An apparatus for application program obfuscation, comprising an application program provider configured to:

receive a reference to a decryption algorithm and a first cryptographic key;

create a key decryption program comprising an instruction stream, said key decryption program configured to perform said decryption algorithm for said first cryptographic key;

apply a cryptographic process to a second cryptographic key together with said first cryptographic key to create an encrypted second cryptographic key;

scramble said encrypted second cryptographic key into said instruction stream using a code obfuscation method indicated by an obfuscation descriptor, said scrambling creating an obfuscated key decryption program, said obfuscation descriptor based at least in part on a target ID; and

send said obfuscated key decryption program.

17. The apparatus of claim 16, said application program provider further configured to send digital content protected by said second cryptographic key.

18. The apparatus of claim 17, said application program provider further configured to send said obfuscated key decryption program together with said digital content.

19. The apparatus of claim 16 wherein said target ID comprises a VM ID.

20. An apparatus for application program obfuscation, comprising a target device configured to:

receive an obfuscated key decryption program comprising an instruction stream configured to perform a decryption algorithm for a first cryptographic key, said obfuscated decryption program having an encrypted second cryptographic key scrambled in said instruction stream, said second cryptographic key encrypted with said first cryptographic key;

execute said program to decrypt said second cryptographic key; and

decrypt digital content using said second cryptographic key.