A CONCEPT FOR VERIFYING THE TRUST DEGREE OF VIDEO DATA STREAMS

Claims

1. A device (16) for checking a video data stream (14) in which the video is encoded for the degree of trust, wherein the device is configured to: applying a hash function (31) to a predetermined portion (13) of the video data stream or data extracted therefrom to obtain a hash value (33); extracting a digital signature (43) from a video data stream; and checking (41) whether the hash value (33) matches the digital signature (43) to determine whether the video data stream is trusted.

2. The device according to claim 1, configured to, when checking (41) whether the hash value corresponds to the digital signature in order to determine whether the video data stream is trusted: decrypting (45) the digital signature to obtain a verification value (47); and checking (49) whether the hash value (33) matches the check value (47).

3. The device according to claim 1 or 2, configured to, when applying a hash function to a predetermined portion (22) of the video data stream or data extracted therefrom, obtain a hash value: restoring the video relative to a predetermined portion to obtain the restored portion of the video, and applying a hash function to the recovered part.

4. A device according to any one of paragraphs 1-3, wherein the device is a decoder (20) configured to: decoding video from a video data stream and decoding a digital signature from a video data stream.

5. A device according to any one of paragraphs 1-4, in which the compliance of the digital signature with a predetermined value is ensured in the event of: equality of a predetermined value with a check value obtained by decrypting the digital signature or a predetermined portion of the check value associated with the predetermined value, or equality with a check value in an additional hashed region, achieved by means of an additional hash function applied to a predefined value or to a concatenation of a value that includes the predefined value.

6. A device according to any one of paragraphs 1-5, configured to obtain a hash function using third information extracted from the data stream.

7. The device of claim 6, wherein the third information comprises a hash function indicator or a third pointer to a third location from which the hash function can be determined, or an identifier of the entity that encoded the video into the video data stream.

8. The device according to any one of paragraphs 1-7, wherein the hash value depends on each bit of a predetermined portion of the video data stream.

9. The device according to any one of paragraphs 1-8, wherein the hash value depends on each bit of a predetermined portion of the video data stream in the entropy encoded region.

10. The apparatus of any one of paragraphs 1-9, wherein the predetermined portion of the video data stream is extended over more than one access unit of the video data stream, such that the hash value depends on bits of more than one access unit.

11. A device according to any one of paragraphs 1-10, configured to check the video data stream for a degree of trust additionally by checking that the hash function is correct, by checking whether the parameterization or identifier of the hash function corresponds to the digital signature.

12. A device according to any of the preceding claims, adapted to provide a hash value for subjecting, along with an additional hash value obtained by applying a hash function or another hash function to a portion of a media stream accompanying a video data stream, or additional data extracted therefrom, to a verification of the degree of trust of the video data stream combined with the media stream.

13. A decoder (20) for decoding video from a video data stream (14), wherein the decoder is configured to: decoding (63) a digital signature (43) from a video data stream; subjecting the digital signature of the video data stream to verification of its trust level by means of: applying a hash function (31) to a predetermined portion (13) of the video data stream or data (62) extracted therefrom to obtain a hash value (33), and checking (41) whether the hash value matches the digital signature to determine whether the video data stream is trusted.

14. The decoder of claim 13, wherein checking the video data stream for a degree of trust includes: decrypting the digital signature to obtain the verification value; and checking whether the hash value matches the check value.

15. The decoder of claim 13 or 14, wherein applying a hash function to a predetermined portion of the video data stream or data extracted therefrom to obtain a hash value comprises: restoring the video relative to a predetermined portion to obtain a restored portion of the video, and applying a hash function to the recovered portion.

16. A decoder according to any one of paragraphs 13-15, in which the compliance of the digital signature with a predetermined value is ensured in the event of: equality of a predetermined value with a check value obtained by decrypting the digital signature or a predetermined portion of the check value associated with the predetermined value, or equality with a check value in an additional hashed region, achieved by means of an additional hash function applied to a predefined value or to a concatenation of a value that includes the predefined value.

17. A decoder according to any one of paragraphs 13-16, configured to obtain a hash function using third information extracted from the data stream.

18. The decoder of claim 17, wherein the third information comprises a hash function indicator or a third pointer to a third location from which the hash function can be determined, or an identifier of the entity that encoded the video into the video data stream.

19. A decoder according to any one of paragraphs 13-18, wherein the hash value depends on each bit of a predetermined portion of the video data stream.

20. A decoder according to any one of paragraphs 13-19, wherein the hash value depends on each bit of a predetermined portion of the video data stream in the entropy coded region.

21. A decoder according to any one of paragraphs 13-20, wherein the predetermined portion of the video data stream is extended over more than one access unit of the video data stream, such that the hash value depends on bits of more than one access unit.

22. A decoder according to any one of paragraphs 13-21, in which checking the video data stream for a degree of trust includes checking that the hash function is correct by checking whether the parameterization or identifier of the hash function matches the digital signature.

23. A decoder according to any one of paragraphs 13-22, adapted to provide a hash value for subjecting, along with an additional hash value obtained by applying a hash function or another hash function to a portion of the multimedia stream accompanying the video data stream, or additional data extracted therefrom, to a check of the degree of trust of the video data stream combined with the multimedia stream.

24. A device (15) for generating a stream (14) of video data into which video is encoded, being checked for a degree of trust, wherein the device is configured to: applying a hash function (31) to a predetermined portion (13) of the video data stream or data extracted therefrom to obtain a hash value (33); calculating a digital signature (43) based on the hash value (33) to digitally sign the hash value (33); and inserting (77) a digital signature (43) into a video data stream (14), thereby making it possible to determine whether the video data stream is trusted by checking whether the hash value (33) matches the digital signature (43).

25. The device according to item 24, configured to calculate a digital signature based on a hash value by means of: generating a check value based on the hash value, encryption of the verification value to obtain a digital signature.

26. The device of claim 24 or 25, wherein applying a hash function to a predetermined portion of the video data stream or data extracted therefrom to obtain a hash value comprises: restoring the video relative to a predetermined portion to obtain a restored portion of the video, and applying a hash function to the recovered portion.

27. The device according to any one of paragraphs 24-26, wherein the device is an encoder configured to: encoding video into a video data stream and encoding a digital signature into a video data stream.

28. A device according to any one of paragraphs 24-27, configured to insert into the data stream third information from which a hash function can be obtained.

29. The device of claim 28, wherein the third information comprises a hash function indicator or a third pointer to a third location from which the hash function can be determined, or a device identifier.

30. The device according to any one of paragraphs 24-29, wherein the hash value depends on each bit of a predetermined portion of the video data stream.

31. The device according to any one of paragraphs 24-30, wherein the hash value depends on each bit of a predetermined portion of the video data stream in the entropy encoded region.

32. The apparatus of any one of paragraphs 24-31, wherein the predetermined portion of the video data stream is extended over more than one access unit of the video data stream, such that the hash value depends on bits of more than one access unit.

33. A device according to any one of paragraphs 24-32, configured to calculate a digital signature additionally based on, and due to this, a digital signature, parameterization or identifier of the hash function.

34. A method (160) for checking a video data stream (14) in which a video is encoded for a degree of trust, wherein the method comprises: applying (131) a hash function (31) to a predetermined portion of the video data stream or data extracted therefrom to obtain a hash value (33); extracting (161) a digital signature (43) from a video data stream; and checking (141) whether the hash value (33) matches the digital signature (43) to determine whether the video data stream is trusted.

35. A method (200) for decoding video from a video data stream (14), comprising: decoding (163) a digital signature (43) from a video data stream; subjecting the digital signature of a video data stream to verification of its trust level by means of: applying (131) a hash function (31) to a predetermined portion (13) of the video data stream or data (62) extracted therefrom to obtain a hash value (33), and checking (141) whether the hash value matches the digital signature to determine whether the video data stream is trusted.

36. A method (15) for generating a stream (14) of video data into which a video is encoded that is checked for a degree of trust, wherein the method comprises: applying (131) a hash function (31) to a predetermined portion (13) of the video data stream or data extracted therefrom to obtain a hash value (33); calculating (171) a digital signature (43) based on the hash value (33) for digitally signing the hash value (33); and inserting (177) a digital signature (43) into a video data stream (14), thereby making it possible to determine whether the video data stream is trusted by checking whether the hash value (33) matches the digital signature (43).

37. A method (15) for storing video, comprising a step in which store a video data stream on a digital storage medium, whereby the video data stream is encoded and its verifiability for the degree of trust is ensured by means of: applying (131) a hash function (31) to a predetermined portion (13) of the video data stream or data extracted therefrom to obtain a hash value (33), calculating (171) a digital signature (43) based on the hash value (33) for digitally signing the hash value (33), and inserting (177) a digital signature (43) into a video data stream (14), thereby making it possible to determine whether the video data stream is trusted by checking whether the hash value (33) matches the digital signature (43).

38. A method (15) for transmitting a video data stream, wherein the video data stream is encoded with video and is verifiable for the degree of trust by means of: applying (131) a hash function (31) to a predetermined portion (13) of the video data stream or data extracted therefrom to obtain a hash value (33); calculating (171) a digital signature (43) based on the hash value (33) for digitally signing the hash value (33); and inserting (177) a digital signature (43) into a video data stream (14), thereby making it possible to determine whether the video data stream is trusted by checking whether the hash value (33) matches the digital signature (43).

39. A non-volatile digital data carrier on which a video data stream generated by the method according to paragraph 36 is stored.