Method and apparatus for using counter-mode encryption to protect image data in frame buffer of a video compression system
View Patent ↗Certain aspects for protecting image data in a video compression system may include encrypting image data utilizing counter-mode scrambling. The encrypted image data may be buffered in at least one frame buffer. The buffered encrypted image data may be decrypted by utilizing counter-mode descrambling.
1. A method for protecting image data in a video compression system, the method comprising:
performing by one or more processors and/or circuits, functions comprising:
encrypting image data utilizing counter-mode scrambling, said encrypting based on calculation of a row size of an encryption cipher; and
buffering said encrypted image data in at least one frame buffer.
2. The method according to claim 1 , said functions comprising initializing a counter-mode scrambler counter to perform said counter-mode scrambling.
3. The method according to claim 2 , wherein counter values for said counter mode scrambler counter utilized for said encrypting are pixel addressable.
4. The method according to claim 1 , said functions comprising loading an encryption key to perform said counter-mode scrambling.
5. The method according to claim 1 , said functions comprising generating a ciphertext of said encrypted image data based on said calculated row size of said encryption cipher.
6. The method according to claim 5 , said functions comprising generating a pad E K (ctr)∥E K (ctr+1)∥E K (ctr+2)∥ . . . ∥E K (ctr+m), where m is an integer, of said encryption cipher utilizing said calculated row size, where E K (X) denotes encipherment of an n-bit block X using an encryption key K and a block cipher E and ctr is a counter-mode scrambler counter.
7. The method according to claim 1 , said functions comprising storing said encrypted image data along with its corresponding horizontal pixel address in an internal random access memory (RAM).
8. The method according to claim 1 , said functions comprising arranging said buffered said encrypted image data in raster scan order.
9. The method according to claim 1 , said functions comprising generating said encrypted image data by exclusive-oring (XORing) at least one plaintext string M of said image data and first |M| bits of a generated pad E K (ctr)∥E K (ctr+1)∥E K (ctr+2)∥ . . . ∥E K (ctr+m), where m is an integer.
10. The method according to claim 9 , said functions comprising pre-processing said generated pad E K (ctr)∥E K (ctr+1)∥E K (ctr+2)∥ . . . ∥E K (ctr+m), where m is said integer, using spare processing cycles.
11. The method according to claim 1 , said functions comprising protecting said buffered said encrypted image data utilizing said counter-mode scrambling, wherein said buffered said encrypted image data is compressed.
12. A method for protecting image data in a video compression system, the method comprising:
performing by one or more processors and/or circuits, functions comprising:
buffering encrypted image data in at least one frame buffer; and
decrypting said buffered encrypted image data utilizing counter-mode descrambling, said decrypting based on calculation of a row size of a decryption cipher.
13. The method according to claim 12 , said functions comprising initializing a counter-mode descrambler counter to perform said counter-mode descrambling.
14. The method according to claim 13 , wherein counter values for said counter mode descrambler counter utilized for said decrypting are pixel addressable.
15. The method according to claim 12 , said functions comprising loading a decryption key to perform said counter-mode descrambling.
16. The method according to claim 12 , said functions comprising decrypting a ciphertext of said encrypted image data based on said calculated row size of said decryption cipher.
17. The method according to claim 16 , said functions comprising generating a pad E K (ctr)∥E K (ctr+1)∥E K (ctr+2)∥ . . . ∥E K (ctr+m), where m is an integer, of said decryption cipher utilizing said calculated row size, where E K (X) denotes decipherment of an n-bit block X using a decryption key K and a block cipher E and ctr is a counter-mode descrambler counter.
18. The method according to claim 12 , said functions comprising storing said buffered encrypted image data along with its corresponding horizontal pixel address in an internal random access memory (RAM).
19. The method according to claim 12 , said functions comprising arranging said buffered encrypted image data in raster scan order.
20. The method according to claim 12 , said functions comprising generating said decrypted said buffered encrypted image data by exclusive-oring (XORing) at least one ciphertext C of said buffered encrypted image data and first |C| bits of a generated pad E K (ctr)∥E K (ctr+1)∥E K (ctr+2)∥ . . . ∥E K (ctr+m), where m is an integer.
21. The method according to claim 20 , said functions comprising pre-processing said generated pad E K (ctr)∥E K (ctr+1)∥E K (ctr+2)∥ . . . ∥E K (ctr+m), where m is said integer, using spare processing cycles.
22. The method according to claim 12 , said functions comprising protecting said buffered said encrypted image data utilizing said counter-mode descrambling, wherein said buffered said encrypted image data is compressed.